In a message dated 01/04/2006, allan.coleman@............ writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>Talking=20 of capturing planned "bumps", mark this one on your calendar also.=20
http://www.worldjumpday.org/

Comments, thoughts etc from anyone= on=20 this event?
Hi Allan,

The Earth's mass is app 6.10^24 kg. The populat= ion=20 is 6.6.10^9. If the average weight were (guess) 50 kg, this would make 3.3.1= 0^11=20 kg. This gives a ratio of 1.8.10^13 which is slightly small.
Perhaps one should look at what other motives t= here=20 could be for promoting this event?

Regards,

Chris Chapman
Subject: Re: Man Made Quake From: ian ian@........... Date: Sat, 01 Apr 2006 19:36:36 +0100 conservation of angular momentum might also influence things even if the orbit was changed (temporarily). Kepler's laws of motion are kind of against you too. You also have a cancellation effect caused by the jumping forces being on opposite sides of the planet, sort of. It's more like 1st of April stuff, though to set up a website just for that is a bit extreme... Ian ChrisAtUpw@....... wrote: > In a message dated 01/04/2006, allan.coleman@............ writes: > > Talking of capturing planned "bumps", mark this one on your > calendar also. > http://www.worldjumpday.org/ > > Comments, thoughts etc from anyone on this event? > > Hi Allan, > > The Earth's mass is app 6.10^24 kg. The population is 6.6.10^9. If > the average weight were (guess) 50 kg, this would make 3.3.10^11 kg. > This gives a ratio of 1.8.10^13 which is slightly small. > Perhaps one should look at what other motives there could be for > promoting this event? > > Regards, > > Chris Chapman conservation of angular momentum might also influence things even if the orbit was changed (temporarily).  Kepler's laws of motion are kind of against you too.  You also have a cancellation effect caused by the jumping forces being on opposite sides of the planet, sort of.

It's more like 1st of April stuff, though to set up a website just for that is a bit extreme...

Ian

ChrisAtUpw@....... wrote:
In a message dated 01/04/2006, allan.coleman@............ writes:
Talking of capturing planned "bumps", mark this one on your calendar also.
http://www.worldjumpday.org/

Comments, thoughts etc from anyone on this event?
Hi Allan,

The Earth's mass is app 6.10^24 kg. The population is 6.6.10^9. If the average weight were (guess) 50 kg, this would make 3.3.10^11 kg. This gives a ratio of 1.8.10^13 which is slightly small.
Perhaps one should look at what other motives there could be for promoting this event?

Regards,

Chris Chapman
In a message dated 31/03/2006, jpopelish@........ writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>Is=20 anyone planning on trying to capture this=20 bump?
http://www.military.com/NewsContent/0,13319,92910,00.html
<= /BLOCKQUOTE>
>>    the spectacle of detonating a 700-ton=20 (635-metric ton) explosive in the Nevada desert

It might be helpful if the weights were correct= ly=20 defined. There are metric tonnes, short tons and long tons, but there i= s no=20 such animal as a 'metric ton'.

>>    James Tegnelia, head of the Defense Thr= eat=20 Reduction Agency, a Pentagon unit that is working on technical aspects of ho= w to=20 destroy deeply buried enemy weapons.

There are already quite a few nuclear ground bu= rst=20 depressions at various test sites, which James could measure; Enewetak=20= in=20 the Marshall Islands, for instance.
If James had read up the history of WW II, he m= ight=20 have heard about deep penetration 'Earthquake' bombs for destroying undergro= und=20 sites. This is the only effective way that was found to destroy a deepl= y=20 buried installation. There are deep bunkers in Europe which were destro= yed=20 this way in WW II, but which could be studied. How about the installations i= n=20 Iraq?
I would be interested to know how the military=20 intend to detonate this amount of AN/FO? What about the toxic by-products? C= heck=20 which way the wind is blowing on the 2nd....

Regards,

Chris Chapman
Subject: Re: Man Made Quake From: ian ian@........... Date: Tue, 04 Apr 2006 18:03:10 +0100 the comparrison is deeply flawed. A metric tonne is a unit of mass, a ton is a unit of force. Someone screwed up significantly when we went metric. It should have been Newtons or Kilo-Newtons for measuring weight. Ian. ChrisAtUpw@....... wrote: > In a message dated 31/03/2006, jpopelish@........ writes: > > Is anyone planning on trying to capture this bump? > http://www.military.com/NewsContent/0,13319,92910,00.html > > >> the spectacle of detonating a 700-ton (635-metric ton) explosive > in the Nevada desert > > It might be helpful if the weights were correctly defined. There > are metric tonnes, short tons and long tons, but there is no such > animal as a 'metric ton'. > > >> James Tegnelia, head of the Defense Threat Reduction Agency, a > Pentagon unit that is working on technical aspects of how to destroy > deeply buried enemy weapons. > > There are already quite a few nuclear ground burst depressions at > various test sites, which James could measure; Enewetak in the > Marshall Islands, for instance. > If James had read up the history of WW II, he might have heard > about deep penetration 'Earthquake' bombs for destroying underground > sites. This is the only effective way that was found to destroy a > deeply buried installation. There are deep bunkers in Europe which > were destroyed this way in WW II, but which could be studied. How > about the installations in Iraq? > I would be interested to know how the military intend to detonate > this amount of AN/FO? What about the toxic by-products? Check which > way the wind is blowing on the 2nd.... > > Regards, > > Chris Chapman the comparrison is deeply flawed.  A metric tonne is a unit of mass, a ton is a unit of force.  Someone screwed up significantly when we went metric.  It should have been Newtons or Kilo-Newtons for measuring weight.

Ian.

ChrisAtUpw@....... wrote:
In a message dated 31/03/2006, jpopelish@........ writes:
Is anyone planning on trying to capture this bump?
http://www.military.com/NewsContent/0,13319,92910,00.html
>>    the spectacle of detonating a 700-ton (635-metric ton) explosive in the Nevada desert

It might be helpful if the weights were correctly defined. There are metric tonnes, short tons and long tons, but there is no such animal as a 'metric ton'.

>>    James Tegnelia, head of the Defense Threat Reduction Agency, a Pentagon unit that is working on technical aspects of how to destroy deeply buried enemy weapons.

There are already quite a few nuclear ground burst depressions at various test sites, which James could measure; Enewetak in the Marshall Islands, for instance.
If James had read up the history of WW II, he might have heard about deep penetration 'Earthquake' bombs for destroying underground sites. This is the only effective way that was found to destroy a deeply buried installation. There are deep bunkers in Europe which were destroyed this way in WW II, but which could be studied. How about the installations in Iraq?
I would be interested to know how the military intend to detonate this amount of AN/FO? What about the toxic by-products? Check which way the wind is blowing on the 2nd....

Regards,

Chris Chapman
Subject: Re: Man Made Quake From: ChrisAtUpw@....... Date: Tue, 4 Apr 2006 14:27:29 EDT In a message dated 04/04/2006, ian@........... writes: the comparrison is deeply flawed. A metric tonne is a unit of mass, a ton is a unit of force. Someone screwed up significantly when we went metric. It should have been Newtons or Kilo-Newtons for measuring weight. Ian. Hi Ian, No, it should not be defined as the force. If it were, the actual quantity (mass) would vary from place to place. The ton in commerce is also mass. Going metric wasn't a 'screw up'? Regards, Chris Chapman
In a message dated 04/04/2006, ian@........... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>the=20 comparrison is deeply flawed.  A metric tonne is a unit of mass, a to= n is=20 a unit of force. Someone screwed up significantly when we went metric= .. It=20 should have been Newtons or Kilo-Newtons for measuring=20 weight.

Ian.
Hi Ian,

No, it should not be defined as the force. If i= t=20 were, the actual quantity (mass) would vary from place to place. The ton in=20 commerce is also mass. Going metric wasn't a 'screw up'?

Regards,

Chris Chapman
Subject: Re: Man Made Quake From: ian ian@........... Date: Tue, 04 Apr 2006 19:45:01 +0100 at the risk of religious wars(!), the "kilo" is subject to variation from place to place because we use a weighing machine to measure it! Sigh. :-) Ian ChrisAtUpw@....... wrote: > In a message dated 04/04/2006, ian@........... writes: > > the comparrison is deeply flawed. A metric tonne is a unit of > mass, a ton is a unit of force. Someone screwed up significantly > when we went metric. It should have been Newtons or Kilo-Newtons > for measuring weight. > > Ian. > > Hi Ian, > > No, it should not be defined as the force. If it were, the actual > quantity (mass) would vary from place to place. The ton in commerce is > also mass. Going metric wasn't a 'screw up'? > > Regards, > > Chris Chapman at the risk of religious wars(!), the "kilo" is subject to variation from place to place because we use a weighing machine to measure it!

Sigh.

:-)

Ian

ChrisAtUpw@....... wrote:
In a message dated 04/04/2006, ian@........... writes:
the comparrison is deeply flawed.  A metric tonne is a unit of mass, a ton is a unit of force. Someone screwed up significantly when we went metric. It should have been Newtons or Kilo-Newtons for measuring weight.

Ian.
Hi Ian,

No, it should not be defined as the force. If it were, the actual quantity (mass) would vary from place to place. The ton in commerce is also mass. Going metric wasn't a 'screw up'?

Regards,

Chris Chapman
I agree 100% with Bob Hammond.  I am not interested in&nbs= p;anyone's personal political opinions posted on PSN.
Al Hrubetz
Subject: Winsdr remote station test From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Tue, 04 Apr 2006 23:01:10 +0000 Hi all I want to know if somebody is willing to test with me the remote option in winsdr, i want to test both server and the client option. I have a fast adsl, so speed is not the problem on my end. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Divine Strake -- Man Made Quake From: ChrisAtUpw@....... Date: Tue, 4 Apr 2006 22:40:54 EDT In a message dated 04/04/2006, geodynamics@....... writes: I'm not at all amused about the upcoming "event" Hi Tim, Thanks for the useful reference information. It will be most interesting to observe what magnitude of quake is actually produced by the known mass of explosive and how the 'signature' varies with distance and soil type. And if anything does go wrong, you will just get some well distributed airbourne fertiliser, but do avoid the downwind plume. It could have fine silicate material (carcinogenic) and N2O. Regards, Chris Chapman
In a message dated 04/04/2006, geodynamics@....... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>I'm not=20 at all amused about the upcoming "event"
Hi Tim,

Thanks for the useful reference information. It= =20 will be most interesting to observe what magnitude of quake is actually prod= uced=20 by the known mass of explosive and how the 'signature' varies wi= th=20 distance and soil type.
And if anything does go wrong, you will just ge= t=20 some well distributed airbourne fertiliser, but do avoid the downwind plume.= It=20 could have fine silicate material (carcinogenic) and N2O.

Regards,

Chris Chapman
Hi Jon,

If you go to http://neic.usgs.gov/neis/t= ravel_times/ you=20 can download travel tiem P-S interval graphs. These are average times, but t= he=20 should be quite accurate.

Regards,

Chris Chapman
In a message dated 08/04/2006, greensky@.............. writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>This may=20 be of interest. It's an article dealing with the electronics of infrasound= =20 detection using simple (cheap) electret condenser microphones.
&n= bsp;=20 http://earth.unh.edu/johnson/MICROPHONES/ISLA14.pdf
=20 http://earth.unh.edu/johnson/MICROPHONES/J4.pdf
Hi Arie,

Also have a look at http://earth.unh= ..edu/johnson/MICROPHONES/ISLA4.pdf I=20 think that this probably gives more realistic measurements.
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>While on=20 holidays I plan to construct this device. It
will be my third sensor=20 dealing with infrasound.
Good luck!
The problems with these microphones is tha= t=20 they don't really go to low enough frequencies and they do drift with=20 temperature.
The circuits described could benefit from a thr= ee=20 or four pole low pass cut-off filter.

You can get greatly extended LF range and reduc= ed=20 noise using a 2" electret piezo speaker as the sensor. They have a capa= city=20 of ~65 nF, so with a 47 M Ohm input impedance, you can get a Tc of 3 se= c,=20 corresponding to a period of 19 sec, 0.05Hz.
The straight sided 1L "food" flasks can be= =20 modified as low temperature drift capacities. I use 100 M Ohm to g= et=20 to 40 sec period with an OPA604 opamp.
It is an advantage to fill the capacity with th= e=20 lowest density polyurethane foam. This ensures a near isothermal=20 pressure response as opposed to an adiabatic / slump response and gives= =20 about 40% more output. The pressure / temperature relaxation time constant o= f=20 this system seems to be about 0.1 sec.
The thermal drift can be reduced if necessary b= y=20 adding candle wax to the inside of the flask to increase the 'thermal mass'.= The=20 thermal time constant of an empty flask for ambient=20 temperature changes may be about 1/2 hr.
You can also use a screw top glass jar with a=20 restriction tube as a simple series low pass RC input filter to limit the pu= lse=20 / noise response.
You need to use a ~constant=20 disk temperature to avoid LARGE voltage drifts.
As with all sensitive LF microphones, you do ne= ed=20 to limit the wind noise, preferably with a loop of porous irrigation hose, m= aybe=20 10 to 30 m diameter, with solid cross connecting tubes to the sens= or=20 in the centre.

Panasonic Electret Condenser Microphone WM-034DM
Hi-Tech Enterprises, Inc.=20 http://www.videoequipment.com

(Note they are a discontinued line)
ht= tp://www.panasonic.com/industrial/components/audio/aud_mic.htm

If you buy the CURRENT Panasoic WM61A, you will= get=20 a higher sensitivity. I suspect that the VLF response is likely to be= =20 similar. You can also use these for intruder detection. You can't open a win= dow=20 or a door without getting quite a large signal.

There is a comprehensive web page giving detail= s of=20 several types of infrasonic sensor at http:= //earth.unh.edu/johnson/MICROPHONES/microphone_list.html
This is worth serious attention for anyone=20 interested in infrasound.

Regards,

Chris Chapman
Subject: April starts quiet From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Sun, 09 Apr 2006 06:35:57 +0000 Hi all Since i got my geophone to record earthquakes there has been hig and low top in earthquake activiti. To this day Febuary has been the most busy one, with 90 files (all three axis, z,n-s,e-w). Mars only had 69 files. January only had 12 files, but i lost many event becose of a wrong configuration at the time. So far i have only detected one event in April (3 files), bad weather have limited my options in detecting earthquakes past two weeks, but i hope that most of the winter storm season is over. I have lost two event becose the geohone was offline at the time. But it has been my experiance that following this type of quiet time, there is going to come a time with alot of earthquakes, problay a time simluar to that one in Febuary. In other news, i am going to update my webpage with the tremor plots soon. The webpage is going to be split up in two parts this time. One Icelandic and other English. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Man Made Quake From: Barry Lotz barry_lotz@............. Date: Mon, 10 Apr 2006 06:31:03 -0700 (PDT) Hi All If I remember my physics, mass does not vary with location (unless you are traveling very fast) but force does ( f=m*a) . the earths acceleration does vary with location. regards Barry ian wrote: at the risk of religious wars(!), the "kilo" is subject to variation from place to place because we use a weighing machine to measure it! Sigh. :-) Ian ChrisAtUpw@....... wrote: In a message dated 04/04/2006, ian@........... writes: the comparrison is deeply flawed. A metric tonne is a unit of mass, a ton is a unit of force. Someone screwed up significantly when we went metric. It should have been Newtons or Kilo-Newtons for measuring weight. Ian. Hi Ian, No, it should not be defined as the force. If it were, the actual quantity (mass) would vary from place to place. The ton in commerce is also mass. Going metric wasn't a 'screw up'? Regards, Chris Chapman
Hi All
If I remember my physics, mass does not vary with location (unless you are traveling very fast) but force does ( f=m*a) . the earths acceleration does vary with location.
regards
Barry

ian <ian@...........> wrote:
at the risk of religious wars(!), the "kilo" is subject to variation from place to place because we use a weighing machine to measure it!

Sigh.

:-)

Ian

ChrisAtUpw@....... wrote:
In a message dated 04/04/2006, ian@iasmith.com writes:
the comparrison is deeply flawed.  A metric tonne is a unit of mass, a ton is a unit of force. Someone screwed up significantly when we went metric. It should have been Newtons or Kilo-Newtons for measuring weight.

Ian.
Hi Ian,

No, it should not be defined as the force. If it were, the actual quantity (mass) would vary from place to place. The ton in commerce is also mass. Going metric wasn't a 'screw up'?

Regards,

Chris Chapman

Subject: Re: Man Made Quake From: ian ian@........... Date: Mon, 10 Apr 2006 16:11:58 +0100 yes, mass is a constant which is the nice thing about it. Sorry to bring this discussion here, apologies in advance. The problem is that mass and weight are different concepts. When we buy a quantity of goods, like flour for instance, we put the flour on a weighing machine, which measures the weight but, under the metric system, we quote the weight in units of mass (Kg). Now if we buy 10 Kg of flour in Reykjavik then take it and the measuring machine to Panama and measure out another 10 Kg, we will find that the two 10 Kg bags of flour are different (by a tiny amount). This takes us back to the original (correct) premise that mass does not vary and so there is something wrong with our experiment. The something wrong is that we used a weighing machine (instead of a "massing" machine) and implicitly applied a constant to convert the weight into mass. The constant is the thing that varies with where you are on the Earth and mainly consists of the acceleration due to the Earth's gravity, minus the centrifugal force caused by the Earth's spin. Both contributions vary around the globe. Again, apologies for the non-quaky topic. Ian Barry Lotz wrote: > Hi All > If I remember my physics, mass does not vary with location (unless > you are traveling very fast) but force does ( f=m*a) . the earths > acceleration does vary with location. > regards > Barry > > > ian wrote: > > at the risk of religious wars(!), the "kilo" is subject to > variation from place to place because we use a weighing machine to > measure it! > > Sigh. > > :-) > > Ian > > > ChrisAtUpw@....... wrote: > >> In a message dated 04/04/2006, ian@........... writes: >> >> the comparrison is deeply flawed. A metric tonne is a unit >> of mass, a ton is a unit of force. Someone screwed up >> significantly when we went metric. It should have been >> Newtons or Kilo-Newtons for measuring weight. >> >> Ian. >> >> Hi Ian, >> >> No, it should not be defined as the force. If it were, the >> actual quantity (mass) would vary from place to place. The ton in >> commerce is also mass. Going metric wasn't a 'screw up'? >> >> Regards, >> >> Chris Chapman > > yes, mass is a constant which is the nice thing about it.

Sorry to bring this discussion here, apologies in advance.

The problem is that mass and weight are different concepts.  When we buy a quantity of goods, like flour for instance, we put the flour on a weighing machine, which measures the weight but, under the metric system, we quote the weight in units of mass (Kg).

Now if we buy 10 Kg of flour in Reykjavik then take it and the measuring machine to Panama and measure out another 10 Kg, we will find that the two 10 Kg bags of flour are different (by a tiny amount).  This takes us back to the original (correct) premise that mass does not vary and so there is something wrong with our experiment.

The something wrong is that we used a weighing machine (instead of a "massing" machine) and implicitly applied a constant to convert the weight into mass.  The constant is the thing that varies with where you are on the Earth and mainly consists of the acceleration due to the Earth's gravity, minus the centrifugal force caused by the Earth's spin.  Both contributions vary around the globe.

Again, apologies for the non-quaky topic.

Ian

Barry Lotz wrote:
Hi All
If I remember my physics, mass does not vary with location (unless you are traveling very fast) but force does ( f=m*a) . the earths acceleration does vary with location.
regards
Barry

ian <ian@...........> wrote:
at the risk of religious wars(!), the "kilo" is subject to variation from place to place because we use a weighing machine to measure it!

Sigh.

:-)

Ian

ChrisAtUpw@....... wrote:
In a message dated 04/04/2006, ian@........... writes:
the comparrison is deeply flawed.  A metric tonne is a unit of mass, a ton is a unit of force. Someone screwed up significantly when we went metric. It should have been Newtons or Kilo-Newtons for measuring weight.

Ian.
Hi Ian,

No, it should not be defined as the force. If it were, the actual quantity (mass) would vary from place to place. The ton in commerce is also mass. Going metric wasn't a 'screw up'?

Regards,

Chris Chapman

Subject: Re: Man Made Quake From: "James Hannon" jmhannon@......... Date: Mon, 10 Apr 2006 10:19:29 -0500 There are actually two types of "weighing machines" scales. One uses springs and actually measures force. The other is a balance which compares one mass against another. This type of scale will be accurate in measuring mass as long as there is any gravity at all. ---------- Original Message ---------------------------------- From: ian Reply-To: psn-l@.............. Date: Mon, 10 Apr 2006 16:11:58 +0100 >yes, mass is a constant which is the nice thing about it. > >Sorry to bring this discussion here, apologies in advance. > >The problem is that mass and weight are different concepts. When we buy >a quantity of goods, like flour for instance, we put the flour on a >weighing machine, which measures the weight but, under the metric >system, we quote the weight in units of mass (Kg). > >Now if we buy 10 Kg of flour in Reykjavik then take it and the measuring >machine to Panama and measure out another 10 Kg, we will find that the >two 10 Kg bags of flour are different (by a tiny amount). This takes us >back to the original (correct) premise that mass does not vary and so >there is something wrong with our experiment. > >The something wrong is that we used a weighing machine (instead of a >"massing" machine) and implicitly applied a constant to convert the >weight into mass. The constant is the thing that varies with where you >are on the Earth and mainly consists of the acceleration due to the >Earth's gravity, minus the centrifugal force caused by the Earth's >spin. Both contributions vary around the globe. > >Again, apologies for the non-quaky topic. > >Ian > >Barry Lotz wrote: > >> Hi All >> If I remember my physics, mass does not vary with location (unless >> you are traveling very fast) but force does ( f=m*a) . the earths >> acceleration does vary with location. >> regards >> Barry >> >> >> ian wrote: >> >> at the risk of religious wars(!), the "kilo" is subject to >> variation from place to place because we use a weighing machine to >> measure it! >> >> Sigh. >> >> :-) >> >> Ian >> >> >> ChrisAtUpw@....... wrote: >> >>> In a message dated 04/04/2006, ian@........... writes: >>> >>> the comparrison is deeply flawed. A metric tonne is a unit >>> of mass, a ton is a unit of force. Someone screwed up >>> significantly when we went metric. It should have been >>> Newtons or Kilo-Newtons for measuring weight. >>> >>> Ian. >>> >>> Hi Ian, >>> >>> No, it should not be defined as the force. If it were, the >>> actual quantity (mass) would vary from place to place. The ton in >>> commerce is also mass. Going metric wasn't a 'screw up'? >>> >>> Regards, >>> >>> Chris Chapman >> >> > > -- Jim Hannon http://www.fmtcs.com/web/jmhannon/ 42,11.90N,91,39.26W WB0TXL -- __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Man Made Quake From: ChrisAtUpw@....... Date: Mon, 10 Apr 2006 11:24:17 EDT In a message dated 10/04/2006, ian@........... writes: When we buy a quantity of goods, like flour for instance, we put the flour on a weighing machine, which measures the weight but, under the metric system, we quote the weight in units of mass (Kg). Now if we buy 10 Kg of flour in Reykjavik then take it and the measuring machine to Panama and measure out another 10 Kg, we will find that the two 10 Kg bags of flour are different (by a tiny amount). Hi Ian, Only if you use a force balance. If you use balance scales with weights, or a steelyard, you get no variation, because they measure mass. Regards, Chris Chapman
In a message dated 10/04/2006, ian@........... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>When we=20 buy a quantity of goods, like flour for instance, we put the flour on a=20 weighing machine, which measures the weight but, under the metric system,=20= we=20 quote the weight in units of mass (Kg).

Now if we buy 10 Kg=20= of=20 flour in Reykjavik then take it and the measuring machine to Panama and=20 measure out another 10 Kg, we will find that the two 10 Kg bags of flour a= re=20 different (by a tiny amount).
Hi Ian,

Only if you use a force balance. If you use bal= ance=20 scales with weights, or a steelyard, you get no variation, because they meas= ure=20 mass.

Regards,

Chris Chapman

Ian

James Hannon wrote:
There are actually two types of "weighing machines" scales. One uses springs and actually measures force. The other is a balance which compares one mass against another. This type of scale will be accurate in measuring mass as long as there is any gravity at all.

---------- Original Message ----------------------------------
From: ian <ian@...........>
Date:  Mon, 10 Apr 2006 16:11:58 +0100

yes, mass is a constant which is the nice thing about it.

Sorry to bring this discussion here, apologies in advance.

The problem is that mass and weight are different concepts.  When we buy
a quantity of goods, like flour for instance, we put the flour on a
weighing machine, which measures the weight but, under the metric
system, we quote the weight in units of mass (Kg).

Now if we buy 10 Kg of flour in Reykjavik then take it and the measuring
machine to Panama and measure out another 10 Kg, we will find that the
two 10 Kg bags of flour are different (by a tiny amount).  This takes us
back to the original (correct) premise that mass does not vary and so
there is something wrong with our experiment.

The something wrong is that we used a weighing machine (instead of a
"massing" machine) and implicitly applied a constant to convert the
weight into mass.  The constant is the thing that varies with where you
are on the Earth and mainly consists of the acceleration due to the
Earth's gravity, minus the centrifugal force caused by the Earth's
spin.  Both contributions vary around the globe.

Again, apologies for the non-quaky topic.

Ian

Barry Lotz wrote:

Hi All
If I remember my physics, mass does not vary with location (unless
you are traveling very fast) but force does ( f=m*a) . the earths
acceleration does vary with location.
regards
Barry

ian <ian@...........> wrote:

at the risk of religious wars(!), the "kilo" is subject to
variation from place to place because we use a weighing machine to
measure it!

Sigh.

:-)

Ian

ChrisAtUpw@....... wrote:

In a message dated 04/04/2006, ian@........... writes:

the comparrison is deeply flawed.  A metric tonne is a unit
of mass, a ton is a unit of force. Someone screwed up
significantly when we went metric. It should have been
Newtons or Kilo-Newtons for measuring weight.

Ian.

Hi Ian,

No, it should not be defined as the force. If it were, the
actual quantity (mass) would vary from place to place. The ton in
commerce is also mass. Going metric wasn't a 'screw up'?

Regards,

Chris Chapman

--
Jim Hannon
http://www.fmtcs.com/web/jmhannon/
42,11.90N,91,39.26W
WB0TXL
--
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Hi Chris
This reminds me of a sensor I built years ago with piezoelectric disks. It looked like a giant childs "jack".It was constructed of acrylic sheets and tubing.The center was a glue together cube. It had 6 ~1" diameter tubes about 6" long which radiated out from the center in the 6 perpendicular directions.The end of each of the 6 tubes had a glued on 1" piezo disk.I filled the whole thing with glyserine. I was going to connect the opposing disks in a half wheatstone bridge. The thought was I would have a triaxial accelerometer by measuring the pressure diferences from one side of the liquid mass to the other. When I found out what the response was from a radio shack mag vs frequency plot for  the disk  I thought I would measure no low frequencies and put the contraption aside. Maybe I was incorrect and had chosen the wrong disk. I can still blow the dust off of it.:)
Regards
Barry

ChrisAtUpw@....... wrote:
You can get greatly extended LF range and reduced noise using a 2" electret piezo speaker as the sensor. They have a capacity of ~65 nF, so with a 47 M Ohm input impedance, you can get a Tc of 3 sec, corresponding to a period of 19 sec, 0.05Hz.
The straight sided 1L "food" flasks can be modified as low temperature drift capacities. I use 100 M Ohm to get to 40 sec period with an OPA604 opamp.
It is an advantage to fill the capacity with the lowest density polyurethane foam. This ensures a near isothermal pressure response as opposed to an adiabatic / slump response and gives about 40% more output. The pressure / temperature relaxation time constant of this system seems to be about 0.1 sec.
The thermal drift can be reduced if necessary by adding candle wax to the inside of the flask to increase the 'thermal mass'. The thermal time constant of an empty flask for ambient temperature changes may be about 1/2 hr.
You can also use a screw top glass jar with a restriction tube as a simple series low pass RC input filter to limit the pulse / noise response.
You need to use a ~constant disk temperature to avoid LARGE voltage drifts.
As with all sensitive LF microphones, you do need to limit the wind noise, preferably with a loop of porous irrigation hose, maybe 10 to 30 m diameter, with solid cross connecting tubes to the sensor in the centre.

Panasonic Electret Condenser Microphone WM-034DM
Hi-Tech Enterprises, Inc. http://www.videoequipment.com

(Note they are a discontinued line)
http://www.panasonic.com/industrial/components/audio/aud_mic.htm

If you buy the CURRENT Panasoic WM61A, you will get a higher sensitivity. I suspect that the VLF response is likely to be similar. You can also use these for intruder detection. You can't open a window or a door without getting quite a large signal.

There is a comprehensive web page giving details of several types of infrasonic sensor at http://earth.unh.edu/johnson/MICROPHONES/microphone_list.html
This is worth serious attention for anyone interested in infrasound.

Regards,

Chris Chapman

Subject: SF 'quake simulations From: Bob Barns royb1@........... Date: Tue, 11 Apr 2006 10:46:45 -0400 Hi gang, http://earthquake.usgs.gov/regional/nca/1906/simulations/ offers some simulations of the San Francisco 'quake. Bob __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: Man Made Quake From: "Jack Ivey" ivey@.......... Date: Tue, 11 Apr 2006 16:51:28 -0400 Just to pound this into the ground a little more... 1 pound force =3D force unit commonly known as a pound 1 pound mass =3D mass that produces 1 pound force in 1 g (32.17 = ft/sec^2)=20 gravitational field 1 slug =3D mass that accelerates at 1 foot/sec^2 when acted on by=20 1 pound force 1 poundal =3D force required to produce a 1 foot/sec^2 acceleration of a 1 pound mass With units like this, who needs SI? J. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Man Made Quake From: "Geoffrey" gmvoeth@........... Date: Tue, 11 Apr 2006 14:43:08 -0700 English unit for mass is only the SLUG Pound is only used as force. At least this is what I was taught at ASU by Professor Voss. It seems to me there is no such animal as a mass named pound. Metric units have Newton's for force and grams for mass. It seems to me that units are terribly misused but I an not absolutely certain about that. The world of science places different meanings on these words then do the laymen. I wish we would all just go metric everything/everywhere. I think most folks are three ounces short of a pound when they use the hyper-complex English measures. All this complexity seems designed to be used by merchants to separate man from his gold. It would be interesting to see a mathematician or a physicist in the white house instead of the ubiquitous politicians. Regards: gmvoeth ----- Original Message ----- From: "Jack Ivey" To: Sent: Tuesday, April 11, 2006 1:51 PM Subject: RE: Man Made Quake Just to pound this into the ground a little more... 1 pound force = force unit commonly known as a pound 1 pound mass = mass that produces 1 pound force in 1 g (32.17 ft/sec^2) gravitational field 1 slug = mass that accelerates at 1 foot/sec^2 when acted on by 1 pound force 1 poundal = force required to produce a 1 foot/sec^2 acceleration of a 1 pound mass With units like this, who needs SI? J. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Man Made Quake From: ChrisAtUpw@....... Date: Tue, 11 Apr 2006 19:33:19 EDT In a message dated 11/04/2006, gmvoeth@........... writes: English unit for mass is only the SLUG Pound is only used as force. Hi Geoff, The ounce, pound, ton, slug, gm, kg and tonne are all mass units. See. _http://www.kayelaby.npl.co.uk/units_and_fundamental_constants/1_1/1_1_3.html_ (http://www.kayelaby.npl.co.uk/units_and_fundamental_constants/1_1/1_1_3.html) Regards, Chris Chapman
In a message dated 11/04/2006, gmvoeth@........... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>English=20 unit for mass is only the SLUG
Pound is only used as=20 force.
Hi Geoff,

The ounce, pound, ton, slug, gm, kg and tonne a= re=20 all mass units.
See. http://www.kayelaby.npl.co.uk/units_and_fundamental_constants/1_1/= 1_1_3.html

Regards,

Chris Chapman
In a message dated 12/04/2006, cstaniger@............ writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>I am a=20 junior in college and last summer I build a seismograph for a school=20 project.  The amplifier and filter work great together, but when I=20 connect the power supply to
the amp. and filter the system doesn=E2=80= =99t=20 work.
Hi Charles,

It sounds like the PSU doesn't work properly.=20

Add a fuseholder and a 1/2A fuse in series with= the=20 input winding on the 'live' side.
Add 47 mu F electrolytic + 0.1 mu F cerami= c=20 capacitors between the common line and both the +ve and the -ve supply rails= ..=20 Check for correct polarity. Use components rated 16V or preferably=20 more..
Check the wiring for correct connections. Note=20= that=20 7812 and 7912 Voltage Regulators have different pin out=20 connections!! Check for good soldered joints and no 'solder bridges= '.=20 The regulators should each have clip on heat sinks, electrically isolated fr= om=20 each other.
Connect a multimeter to the common output.
On AC volts, the readings on both AC rectifier=20 terminals should be 12 to 13 V.
On DC volts, the two 4,700 mu F capacitors shou= ld=20 read about +16 to +17 V and -16 to -17 V.
On DC volts, the output rails should read +12 a= nd=20 -12 V +/-4%
On AC volts, the output rails should read a few= =20 milli volts.
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>My=20 question is, Does anyone know of any power supply schematics that would wo= rk=20 with my amplifier and filter?
Make the fuse and capacitor additions to the=20 circuit diagram.
http://users.viawest= ..net/~aloomis/seisprea.htm

Hope that this helps.

Regards,

Chris Chapman
Subject: Re: Conference / meetings From: ChrisAtUpw@....... Date: Wed, 12 Apr 2006 18:52:51 EDT In a message dated 12/04/2006, gmvoeth@........... writes: It takes both money and time for the luxury of attending such meetings.. I would recommend to everyone to get something like MSN Messenger installed on their machine then holding a chat conference. You can do a lot of things with that program. But beware it seems once you install it, if you want to get rid of it that will not be as easy. Hi All, The membership of psn is world wide. The current means of communication is via EMail, but without any attachments for diagrams or photographs. This is quite a limitation. I am not sure how many members would want to / can actively participate in a formal on-line conference? Most would probably be interested in 'listening in' to a meeting with several 'theme' papers + discussion groups, centred around seismology. Maybe using WebCams? Maybe focussed lectures / demonstrations on a DVD and discussion groups later on? Can we cope with the various ww recording formats? These lectures could become a valuable 'resource'? We might be able to get Iris / Spi-Net interested? Regards, Chris Chapman
In a message dated 12/04/2006, gmvoeth@........... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000=20 size=3D2>    It takes both money and time for the luxu= ry of=20 attending such meetings.. I would recommend to everyone to get something l= ike=20 MSN Messenger installed on their machine then holding a chat conference. Y= ou=20 can do a lot of things with that program. But beware it seems once you ins= tall=20 it, if you want to get rid of it that will not be as=20 easy.
Hi All,

The membership of psn is world wide. The curren= t=20 means of communication is via EMail, but without any attachments for diagram= s or=20 photographs. This is quite a limitation.

I am not sure how many members would want to /=20= can=20 actively participate in a formal on-line conference? Most would probably be=20 interested in 'listening in' to a meeting with several 'theme' papers +=20 discussion groups, centred around seismology. Maybe using=20 WebCams?
Maybe focussed lectures / demonstrations on a D= VD=20 and discussion groups later on? Can we cope with the various ww recordi= ng=20 formats? These lectures could become a valuable 'resource'?

We might be able to get Iris / Spi-Net interest= ed?=20

Regards,

Chris Chapman

Hi Brett
STM wrote as a solution to LVDTs "The common solution is to use a capacitive bridge transducer, where a moving vane moves between two fixed plates that form a capacitive bridge that is unbalanced by the movement of the vane. With proper geometry, these can be very sensitive and linear over a range of several hundred microns. However, they are difficult to construct and have a working gap of less than a millimeter, and are prone to off axis sensitivity. They usually operate at relatively high frequencies, from khz to mhz, which complicates design and implementation problems" It looks like the AD device would solve some of these concerns. He then goes on to describe the VRDT. I suppose for the VBB sensor this would greatly simplify the electronic design if one can deal with small sensor gaps. I'm not sure about the noise. Does the VBB measure displacements in the 1 ą nm range?   --- Just thinking out loud. I think it greatly depends on what type of sensing one wants to do local,regional or teleseismic. I like the possibility's.
Regards
Barry

Brett Nordgren <Brett3kg@bnordgren.org> wrote:

Meant to say AD7745 / 7746

Sorry,
Brett

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In a message dated 13/04/2006, barry_lotz@............. writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>
Hi Brett
STM wrote as a solution to LVDTs "The common solution is to us= e a=20 capacitive bridge transducer, where a moving vane moves between two fixed=20 plates that form a capacitive bridge that is unbalanced by the movement of= the=20 vane. With proper geometry, these can be very sensitive and linear over a=20 range of several hundred microns.
Hi Barry,

The capacitance in pF =3D 0.0885xAxK / d, where= A is=20 the plate area in sq cm, K is the dielectric constant and d is the plate=20 separation in cm.
With proper design, sensors can be linear over=20= +/-5=20 mm or more. It depends on what you need. It may be difficult to get the nois= e=20 below 1 ppm x range for 10 Hz bandwidth, but it can be done.
However, they are difficult to construct and have a working gap o= f less=20 than a millimetre, and are prone to off axis sensitivity.=20
This is largely incorrect for amateur applicati= ons.=20 If you demand 1nm resolution or better, you do need special materials and=20 construction -> Silver coated Invar / Platinum coated Quartz electrodes.=20

There are three basic types of capacitor sensor= ..=20 You can have a pair of parallel plates excited by sine or square waves with=20= a=20 central sensor plate which moves perpendicular to the plane. This nee= ds=20 voltage detection to be highly linear and has a range limited by=20 the separation of the outer plates - likely to be quite limited. If you= use=20 charge sensing, the linear range is reduced to maybe 1/4. You are likel= y to=20 have to bore holes in the plates to allow adequate airflow as they move.
You can use two pairs of parallel plates with a= =20 central sensor plate moving parallel to the plane - a split stator=20 variable capacitor. The excitation is applied between the pairs of plates on= =20 opposite sides of the sensor plate. Charge detection is usually used with an= =20 electrical connection to central plate. The sensor range depends on=20 the width of the moving plate, which is half the overall stator wi= dth.=20 There is no air flow problem with plate movement.
You can use basically parallel circuit board pl= ates=20 with a pair of excitation strips on one side, a cross coupled square /=20 rectangular sense array on the other and a plate with vertical 'shadow strip= s'=20 moving parallel in between. It is easy to make these out of double si= ded=20 glass circuit board. The central shadow plate does not need to be earth= ed.=20 Only the fixed plates need to be wired up, which is a considerable=20 advantage. The maximum movement is half the square 'cell size'. Aga= in=20 this can be quite large. See Randall Peters' SDC sensor at http://physics.mercer.ed= u/petepag/sens.htm Charge=20 detection is usually used. An array of coupled cells can be used to increase= the=20 sensitivity. It is an advantage to make the shadow plate out of etched doubl= e=20 sided glass board. The 'electrical thickness' is the actual thickness divide= d by=20 the dielectric constant. Having all three boards made from the same material= =20 greatly reduces any thermal drift. There is no air flow problem with plate=20 movement.
They usually operate at relatively high frequencies, from khz to=20= mhz,=20 which complicates design and implementation problems"
Operating at 10 to 50 k Hz is just fine. You ca= n=20 use digital to sine weighted step down counters which give very good sine wa= ves=20 - see http://www.eas= ..slu.edu/People/STMorrissey/index.html =20 Alternatively, you can use a LTC1043 quad chopper switch / oscillator w= ith=20 either sine or square waves. Using sine waves allows you to get a highe= r=20 S/N ratio. XR8038 & especially XR2206 function generators can give quite= a=20 good performance, as can a FET stabilised Wein Bridge oscillator - see http://www.keckec.com/seismo/. Tw= o=20 stages of RC bandpass filter are used in http://psn.quake.net/i= nfo/bb13OperManual.pdf starting=20 with the square wave from a quartz oscillator. For low drift, avoid=20 resonant circuits and diode rectification.
It looks like the AD device would solve some of these=20 concerns.
The concerns seem to be largely illusory in=20 practice.

In a message dated 13/04/2006 14:48:47 GMT Daylight Time,=20 Brett3kg@............. writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>Biggest=20 VRDT problem seems to be its low drive frequency. In a feedback=20
design the large demod filters are prime contributors to loop oscillat= ion=20 problems.
So reduce the filtration and apply a DC + pulse= d=20 feedback? Use another method?
The feedback phase delay is only a problem if y= ou=20 do it this way!
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>>I'm=20 not sure about the noise. Does the VBB measure displacements in the 1=20
>=B1 nm range?

With the sensor plates above, 1LSB=3D0.08nm.&= nbsp;=20 But I think noise is what
determines the useful resolution.  Howe= ver=20 0.3nm / sqrt-Hz and 2.1nm RMS at
50 SPS isn't too shabby.  It wou= ld=20 be interesting to assume a seismic-mass
system and model how this woul= d=20 compare with commercial instruments and
earth-noise models.  I'm=20 betting it won't look so bad.
Have you measured your environmental noise leve= l?=20 Is 2.1 nm a realistic target? The amplitude of the 6 second ocean microseism= s=20 may be from 500 to 15,000 nm!
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2> He=20 then goes on to describe the VRDT. I suppose for the VBB sensor this would= =20 greatly simplify the electronic design if one can deal with small sen= sor=20 gaps. I'm not sure about the noise. Does the VBB measure displacement= s in=20 the 1 =B1 nm range?   --- Just thinking out loud. I think it gre= atly=20 depends on what type of sensing one wants to do local, regional or=20 teleseismic.
Amateur seismometers are usual= ly=20 limited by either microseisms or by environmental noise - we can't usually=20 choose a quiet remote site. I managed to reduce the noise of my LVDT to abou= t 7=20 nm for a 6 mm range at 10 Hz, but my environmental noise is much greater=20 than this.

<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>It would=20 be great to be able to use this with feedback.  No question that
= you=20 could use it for integral feedback, which mainly works below the low=20
frequency roll off (say, below 0.011 Hz).  You could make an awes= ome=20
integrator by digital summing, then feed back with a D/A.  Mid=20 frequency
range (derivative feedback) may not be practical.  Alth= ough=20 you could keep
your beam well centred with integral feedback, without=20 derivative feedback
at higher frequencies, you're limited by the +/- 1= ..0mm=20 (+/- 0.5 mm max, for
linearity) sensor gap.  I'm suspecting that=20 clipping levels in the
mid-frequency range are going to be the biggest= =20 limitation.

So, we may need some 'lateral thinking'=20 here! There are 'problems that you do not need to have' - like:-

The velocity feedback damping does not need to=20= be=20 generated that way!

Neither do we need to use that troublesome desi= gn=20 of capacitative sensor!

***   You can use JUST position +=20 integral current / coil feedback if you ALSO have a quad magne= t +=20 Cu plate for the velocity damping! Trying to provide velocity damping by=20 differentiation and coil feedback is likely to very significantly increase t= he=20 overall circuit noise!  ***

Regards,

Chris Chapman
Subject: Update to my earthquake webpage From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Fri, 14 Apr 2006 01:05:25 +0000 Hi all I have updated my earthquake webpage. I want to know what you think about it and to help me to locate any spelling error that i might have left in the english section of the page. The link to the webpage is in the signature. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: The New Madrid seismic zone From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Fri, 14 Apr 2006 01:37:34 +0000 Hi all I did find this news today about the New madrid seismic zone in the U.S. They think that large earthquake might happen there sometimes in the future. http://science.monstersandcritics.com/news/article_1154951.php/Big_quake_might_ravage_U.S._Midwest Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Honeywell DC001NDR5 sensor From: Barry Lotz barry_lotz@............. Date: Thu, 13 Apr 2006 20:33:44 -0700 (PDT) Hi All Not to get of the current thread but I was thinking of the honeywell pressure transducer. If one has a horizontally oriented cylinder(say 6" long - maybe 2" diameter) filled with a non-evaporative liquid of low viscosity. At each would be a manometer tube attached to the end plates and directed up and partially filled with the liquid. Attach the DC001ndrr5 to one end and maybe leave the manometer tube at the other end open (maybe closed I'm not sure). It would seem that the sensor would measure the pressure difference as the liquid moved horizontally due to seismic motion. I did the math for a column of water 6" long and got g numbers pretty low say 10^-5 for a sensor of ą 125 pa. I don't think there would be fluid flow issues at the manometer ports since the fluid velocities would seem to me low. One would probably have to put the sensor in a sealed container to minimize barometric fluxuations. I think scientific american had something like this years ago but measured the water levels some other way. Regards Barry
Hi All
Not to get of the current thread but I was thinking of the honeywell pressure transducer. If one has a horizontally oriented cylinder(say 6" long - maybe 2" diameter) filled with a non-evaporative liquid of low viscosity. At each would be a manometer tube attached to the end plates and directed up and partially filled with the liquid. Attach the DC001ndrr5 to one end and maybe leave the manometer tube at the other end open (maybe closed I'm not sure). It would seem that the sensor would measure the pressure difference as the liquid moved horizontally due to seismic motion. I did the math for a column of water 6" long and got g numbers pretty low say 10^-5 for a sensor of ą 125 pa. I don't think there would be fluid flow issues at the manometer ports since the fluid velocities would seem to me low. One would probably have to put the sensor in a sealed container to minimize barometric fluxuations. I think scientific american had something like this years ago but measured the water levels some other way.
Regards
Barry
In a message dated 14/04/2006, Brett3kg@............. writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000=20 size=3D2>>           However, they are=20 difficult to construct and have a working gap of
>    &nbs= p;=20      less than a millimetre, and are prone to off axis=20 sensitivity.
>
>    This is largely incorrect for=20 amateur applications. If you demand 1nm
> resolution or better, you= do=20 need special materials and construction.

I'm not sure pure resoluti= on=20 is that hard to come by.  Noise & temperature
sensitivity are= =20 another matter, though.
Hi Brett,

There are ways of reducing the effects of therm= al=20 expansion without using exotic materials. Noise can be greatly reduced using= =20 a dual FET front end on a chopper amplifier. The latest types give abou= t 1=20 nV rms / Root Hz.
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000=20 size=3D2>>      There are three basic types of capacitor= =20 sensor.
>You can have a pair of parallel plates excited by sine or=20 square waves
>with a central sensor plate which moves perpendicular= to=20 the plane. <clip>
There are two major disadvantages with this=20 type.
Movement of the sensor plate displaces air betw= een=20 the plates on both sides. This damping + spring cushion effect dep= ends=20 on the plate size, their separation and on the plate velocity - it vari= es a=20 lot. The traditional methods of reducing these problems involve boring air h= oles=20 in the capacitor plates and evacuating the seismometer case.
This sort of sensor is only linear over the who= le=20 movement range if you use either voltage sensing or a special feed= back=20 circuit with 'floating' power supplies. However, you are critically dependan= t on=20 stray capacity effects. These can be largely compensated for sine wave=20 excitation, but with some difficulty. If you use a charge amplifier, it will= =20 only be approximately linear for 1/3 to 1/4 the available movement range.
Since other designs without these problems are=20 available, why do things the hard way?
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000=20 size=3D2>>     You can use two pairs of parallel plates=20= with a=20 central sensor plate
> moving parallel to the plane=20 <clip>
>     You can use basically=20 parallel circuit board plates with a pair of excitation strips on one side= , a=20 cross coupled square / rectangular sense array on the other and a plate wi= th=20 vertical 'shadow strips' moving parallel in between. It is easy to=20= make=20 these out of double sided glass circuit board. The central shadow pla= te=20 does not need to be earthed. Only the fixed plates need to be wired= up,=20 which is a considerable advantage. The maximum movement is half t= he=20 square 'cell size'. Again this can be quite large. See Randall Peters' SDC= =20 sensor at http://physics.mercer.= edu/petepag/sens.htm Charge=20 detection is usually used. An array of coupled cells can be used to increa= se=20 the sensitivity. It is an advantage to make the shadow plate out of etched= =20 double sided glass board. The 'electrical thickness' is the actual thickne= ss=20 divided by the dielectric constant. Having all three boards made from the=20= same=20 material greatly reduces any thermal drift. There is no air flow problem w= ith=20 plate movement.  <clip>

I'd always assumed that only the= =20 first type had adequate displacement
sensitivity, a couple of orders o= f=20 magnitude greater than the
others. Sounds like I need to go back=20= and=20 check the numbers.
They mostly come down to dL / L considerations.= The=20 larger you make the total range L, the more you need to amplify the sig= nal.=20 It is quite possible to maintain a very high sensitivity by detecting the wh= ole=20 signal range and then adding a high pass filter and more amplification. My L= VDT=20 Lehman sensor allows the first stage to give +/-10V for the allowed +/-10 mm= =20 range. This signal is then put through a high pass filter and the 'AC' compo= nent=20 is amplified further. This allows resolution of a few 10s of nm on my 16 bit= ADC=20 over the whole 10 mm range.
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000=20 size=3D2>>   In a message dated 13/04/2006, Brett3kg@bnordgre= n.org=20 writes:
>Biggest VRDT problem seems to be its low drive frequency. I= n a=20 feedback
>design the large demod filters are prime contributors to l= oop=20 oscillation
>problems.
>     So reduce the=20 filtration and apply a DC + pulsed feedback? Use
> another=20 method?

Can you amplify on this?  Not exactly sure what your'e= =20 proposing, but it
sounds interesting.
If you look at the circuit in http://psn.quake.net/i= nfo/bb13OperManual.pdf two=20 stages of RC bandpass filter are used starting with the square wave fro= m a=20 quartz oscillator. One filter is on the input line to the differential capac= itor=20 sensor and the other on the amplified output from the sensor. The output of=20= the=20 final amplifier has a DC component with a large AC ripple on it at twice the= =20 oscillator frequency. This is applied to the inductive winding of the feedba= ck=20 coil through a parallel RC link to give a low phase error feedback sign= al.=20 If you fully smoothed the output, you would have a greater phase delay. You=20= then=20 add a low pass filter to smooth the signal for the A/D converter.
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000=20 size=3D2>>     The feedback phase delay is only a proble= m if=20 you do it this way!
> >I'm not sure about the noise. Does the VBB= =20 measure displacements in the
> >=B11 nm range?
>
>Wit= h the=20 sensor plates above, 1LSB=3D0.08nm.  But I think noise is=20 what
>determines the useful resolution.  However 0.3nm / sqrt-H= z=20 and 2.1nm RMS at
>50 SPS isn't too shabby.  It would be interes= ting=20 to assume a seismic-mass
>system and model how this would compare wi= th=20 commercial instruments and
>earth-noise models.  I'm betting it= =20 won't look so bad.
>     Have you measured your=20 environmental noise level? Is 2.1 nm a
> realistic target? The=20 amplitude of the 6 second ocean microseisms may be
> from 500 to 15= ,000=20 nm!

Actually 2.1nm was no target.  That's just what I calculat= ed=20 you could get
using the AD7745.  I agree that it is a good bit be= tter=20 than a typical home
site would justify, which is why it looked so=20 interesting.
The lower limit for LVDT measurements is a= bout=20 0.1 nano m. With capacitative sensors you can reduce this by 100. This=20= is=20 far smaller than the background noise limits.
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000=20 size=3D2>>  He then goes on to describe the VRDT. I suppose for th= e VBB=20 sensor this
> would greatly simplify the electronic design if one c= an=20 deal with small
> sensor gaps. I'm not sure about the noise. Does t= he=20 VBB measure
> displacements in the 1 =B1 nm range?   ---=20= Just=20 thinking out loud. I think
> it greatly depends on what type of sen= sing=20 one wants to do local,
> regional or teleseismic.
>  &nb= sp;=20    Amateur seismometers are usually limited by either microseism= s or=20
> by environmental noise - we can't usually choose a quiet remote s= ite.=20 I
> managed to reduce the noise of my LVDT to about 7 nm for a 6 mm= =20 range at
> 10 Hz, but my environmental noise is much greater than=20 this.
>
>     There are 'problems = that=20 you do not need to have' :-
>
>     The=20 velocity feedback damping does not need to be generated that=20 way!
>
>     Neither do we need to use that=20 troublesome design of capacitative sensor!
>
> =20 ***   You can use JUST position + integral current / coil feedba= ck=20 if
> you ALSO have a quad magnet + Cu plate for the velocity dampin= g!=20 Trying
> to provide velocity damping by differentiation and coil=20 feedback is
> likely to very significantly increase the overall cir= cuit=20 noise!  ***

I'm now thinking that's where I was heading, excep= t=20 for retaining the
"perpendicular" capacitance sensor. =20
I suggest that you reconsider the capacitative=20 sensor design. You really don't need pneumatic damping problems and it is=20 helpful to be able to choose your range. If you are trying to measure a few=20 parts in a 15,000 nm signal, you need the lowest noise most linear system th= at=20 you can get. A considerable reduction in expansion coefficient is possible u= sing=20 either conducting paint, evaporated metal, or etched metal on thin pyrex she= et=20 glass. You can stick metal foil onto sheet glass with acrylic adhesive=20= -=20 don't try epoxy unless you prebake the glass to over 150 C. The electrode pl= ates=20 can be made by photo etching.
True chopper amplifier circuits are available.=20 These are immune to 1/f noise. The SDC type sensor offers a great constructi= onal=20 advantage in ease of wiring - no electrical connections are required to the=20 seismic mass - and you can use coaxial screened cable with a charge=20 amplifier.  The design is not too critical on electrode spacing, which=20= can=20 be quite small.
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>Since=20 the AD7746 goes directly from
capacitance to digital, I was hoping to=20= use=20 either a PC or commercial DSP
chip or FPGA to do most of the=20 Position-Velocity derivative and other
shaping.  I like that beca= use=20 that needs minimal analog circuitry and what
you do need (integral cur= rent=20 feedback) is working at virtually DC.  And,
yes, for that to work= you=20 would need a well-damped and stable spring
mass. First-order displacem= ent=20 linearization could be done digitally.  Also you'd need to be sure th= at=20 your displacement sensor range was adequate.
There are two problems associated with either=20 analogue or digital generation of a velocity feedback signal from a position= =20 signal. The generated signal is inherently noisy. You can also run off the e= nd=20 of the voltage or count scale --> system failure. The phase errors /= =20 delays need to be considered / compensated.
It is relatively easy to provide a very quie= t=20 precision velocity feedback signal within the stop limits of the mass=20 movement using either magnet / coil / resistor damping or a quad magnet /=20 variable area damping plate. This uses NO external power OR electronics! Why= 'do=20 things the hard way'?
The http://gravit= y.ucsd.edu/research/OFSEIS/opt_seis.html account=20 claims a reduction in the feedback noise using magnet / coil / resistor= =20 damping.
24 bit DACs are available for positional feedba= ck /=20 integral feedback.

Another factor which can significantly effect t= he=20 overall seismometer performance lies in the design of the suspension system,= as=20 you outlined in your rolling foil design.
The 'art' of being successful lies largely in n= ot=20 making mistakes and in avoiding unnecessary problems and limitations.

Regards,

Chris Chapman
In a message dated 18/04/2006, lcochrane@.............. writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>The=20 discussion last week about the AD7745/6 chip was rather timely. The event=20 files that I have been posting on the event file archive system with the f= ile=20 extension of *.LCTST.PSN are from the new Volksmeter sensor. If you compar= e=20 the LC8 channel of my S-G sensor and the new Volksmeter sensor you will se= e=20 they are similar since they both use a short period pendulum and a=20 displacement pickup.
Hi Larry,

What period compensation are you claiming for t= his=20 sensor?
Do the plots show a compensated velocity /=20 compensated displacement / uncompensated signal, or what?
How are you performing the velocity feedback /=20 damping necessary to stabilise the response?

I note that in your SG EMail reference, you cla= im a=20 flat response from 50 sec to 3 Hz, but remarked that you had to substantiall= y=20 increase the damping to get this. I note that in your latest circuit diagram= ,=20 you seem to have greatly reduced the itegration time and wondered if the cir= cuit=20 values were correct?

Regards,

Chris Chapman

I built a seismometer and I measured my data in currnt and time. I am trying to convert that into wavelength and oscillation. How can I do that?

From:  Larry Cochrane <lcochrane@..............>
To:  psn-l@..............
Subject:  Re: Volksmeter sensor and the AD774x CDC chip
Date:  Wed, 19 Apr 2006 23:40:41 -0700
>Hi Chris,
>
>ChrisAtUpw@....... wrote:
>>
>>In a message dated 18/04/2006, lcochrane@.............. writes:
>>
>>timely.
>>     The event files that I have been posting on the event file
>>archive
>>     system with the file extension of *.LCTST.PSN are from the new
>>     Volksmeter sensor. If you compare the LC8 channel of my S-G
>>sensor
>>     and the new Volksmeter sensor you will see they are similar
>>since
>>     they both use a short period pendulum and a displacement
>>pickup.
>>
>>Hi Larry,
>>      What period compensation are you claiming for this sensor?
>
>>     Do the plots show a compensated velocity / compensated
>>displacement / uncompensated signal, or what?
>>     How are you performing the velocity feedback / damping
>>necessary to stabilise the response?
>
>There is no period compensation in either the SG sensor or the
>Volksmeter (VM). Both use simple damping. The SG sensor has a
>feedback loop but it's just there to damp the pendulum. It might
>make the sensor more stable do to the feedback loop, but I'm not
>sure of that. The VM sensor uses eddy-current damping and has no
>feedback system. Randall will be sending a response to this shorty.
>
>The plots are from the raw data right out of the sensor, but with a
>60 second 2 pole high-pass and 2 Hz 2 pole low-pass filter applied
>to the data before making the GIF image. The event files are the raw
>
>>      I note that in your SG EMail reference, you claim a flat
>>response from 50 sec to 3 Hz, but remarked that you had to
>>substantially increase the damping to get this. I note that in your
>>latest circuit diagram, you seem to have greatly reduced the
>>itegration time and wondered if the circuit values were correct?
>
>Like the VM channel (LCTST) my LC8 channel is pretty much the raw
>data from the pickup except there are two 60 second high-pass
>filters in the signal path. My LC3 channel, the integrated output,
>should have a velocity response from about 1 second, the period of
>the pendulum, to about 50 seconds. I have not made any changes to my
>SG sensor for many years so the value of the integrator parts should
>be the same.
>
>-Larry
>
>
>
>
>__________________________________________________________
>
>Public Seismic Network Mailing List (PSN-L)
>
>To leave this list email PSN-L-REQUEST@.............. with the body
>of the message (first line only): unsubscribe
In a message dated 20/04/2006, lcochrane@.............. writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>> Hi=20 Larry,
>     What period compensation are you claimin= g=20 for this sensor?
>     Do the plots show a compensate= d=20 velocity / compensated displacement
> / uncompensated signal, or=20 what?
>     How are you performing the velocity feedb= ack=20 / damping necessary to
> stabilise the response?

There is no= =20 period compensation in either the SG sensor or the Volksmeter (VM). Both u= se=20 simple damping. The SG sensor has a feedback loop but it's just there to d= amp=20 the pendulum. The VM sensor uses eddy-current damping and has no feedback=20 system.
Randall will be sending a response to this shorty.

The=20 plots are from the raw data right out of the sensor, but with a 60 second=20= 2=20 pole
high-pass and 2 Hz 2 pole low-pass filter applied to the data bef= ore=20 making the GIF
image. The event files are the raw data from the AD7746= =20 chip.
Hi Larry,

The original S/G circuit used a 62.5 sec AC cou= pled=20 integrator with a gain of 10, a 1 sec low pass filter and critical damp= ing.=20 This was to give it an output linear with velocity.
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000=20 size=3D2>>     I note that in your SG EMail reference (<= A=20 href=3D"http://psn.quake.net/freqtest.html">http://psn.quake.net/freqtest.= html),=20 you claim a flat response
> from 50 sec to 3 Hz, but remarked that=20= you=20 had to substantially increase
> the damping to get this. I note tha= t in=20 your latest circuit diagram, you
> seem to have greatly reduced the= =20 itegration time and wondered if the
> circuit values were=20 correct?

Like the VM channel (LCTST) my LC8 channel is pretty much=20= the=20 raw data from the
pickup except there are two 60 second high-pass filt= ers=20 in the signal path. My LC3
channel, the integrated output, should have= a=20 velocity response from about 1 second, the period of the pendulum, to abou= t 50=20 seconds. I have not made any changes to my SG sensor for many years so the= =20 value of the integrator parts should be the same.
The circuit at http://psn.quake.net/sg-schm.gif shows=20 a 100 K Ohm input resistor, a 470 K Ohm feedback resistor and a 2 mu F=20 parallel capacitor. This RC combination rolls off at a period of only 5.9= =20 seconds - a factor of 10 less than we want. This is why I asked if the=20 published circuit values are correct??
Do you still use a 4.7 M Ohm feedback resistor,= =20 like in your previous circuit at http://psn.quake.net/sgproc.gif=  ?
Moreover, there does not seem to be a 1 sec low= =20 pass circuit to produce a velocity response?

It is possible to ''squash'' this sort of humpe= d=20 response by heavy overdamping and a considerable increase in the amplif= ier=20 gain, but you tend to run into serious noise problems.
The original circuit used an input capacitor to= the=20 integrator, which should effectively limit the VLF 1/f noise. A 100 mu=20= F=20 non polar capacitor?

Note that it is usually possible to length= en=20 the period using digital processing - if there is sufficient signal=20 resolution, as seems likely with the VM 24 bit ADC. However, doing this= to=20 a displacement signal is likely to give rather large amplitudes at the low=20 frequencies. Maybe the VM displacement signal could be converted into a velo= city=20 signal?

Regards,

Chris Chapman
Hi Angel/ Dave
I tried to look at the photos w/o success ????. I remembered a Scientific American amateur Scientist artical of 11/1973 which showed a sensitive tilt meter construction ( with Mercury however.) which used capacitive sensors at the ends. Is it similar to yours? While I was blowing the dust of the old issues I ran across the SG seismometer 9/1975 article. This is what started me down the amateur seismologist path.
Regards
Barry

Angel <sismos@..............> wrote:
Hello Jim,

An FMES is a bunch of plumbing filled with water. Well, that is a bit over
simplified but no too much. Fluid Mass Electrolytic Seismometer. Once
you have the knack of it you can make one in just a few hours, not
counting the electronics. With just your left hand it might take you a
bit longer.

Basically two transducer about a meter apart joined by some tubing so
the electrolytic fluid (water and antifreeze) find a level within the
transducers. The transducers form part of a sensitive resistive bridge
which senses the motion of the fluid. Like I said this is over
simplified but not by far.

There is a yahoo group that chats now and then on building them and
trading ideas, you can see some photos at the groups site:

http://groups.yahoo.com/group/fmes/

Dave Nelson is the creator of FMES and he might pipe (no pun intended)
in and say a bit more. Dave might have some more current pictures.

angel

Saturday, April 22, 2006, 11:09:06 AM, you wrote:

> what is a FMES-????
> I broke my right hand so am typing left-handed...jim

> -- Angel wrote:
> Hi All,

> Here is a jpeg of how the Siberia 7.7 (or 7.6) looked like here in
> Panama on a 1 meter long FMES oriented N/S with a 24 bit digitizer.

> http://www.volcanbaru.com/quakes/FMES_Siberia_7-7.jpg

> Each line is 30 minutes long.

> FMES's are easy to build and are great for tele-seismic stuff and
> pretty good for the local events also.

> regards,

> Angel

Subject: Re[2]: Siberia 7.6 on an FMES From: Angel sismos@.............. Date: Sat, 22 Apr 2006 21:59:35 +0000 Hello Erich and Bob, Thanks, but all of the credit goes to Dave Nelson for dreaming up the idea and spending countless hours on this project. That particular FMES is in a vault and I live in a generally quite place. The vault is about 60 yards from the house and I get the signal to the house via TCP/IP. The digitizer is a single channel 24 bit \$150 device from www.symres.com which goes into an Earthworm transport buffer and then published on the internet. My other FMES's are on a WinSDR system. I must add that my Winsdr board also exports to an Earthworm system. In its most simple from and FMES can be built in an afternoon with stuff you can get a hardware store. The fluid is made conductive with distilled water a .5% antifreeze and .1% anti-foam (Rug Doctor fluid). http://www.volcanbaru.com/fmes/an_fmes.JPG a newer model http://www.volcanbaru.com/fmes/a_Tranducer.JPG Transducer end http://www.volcanbaru.com/fmes/coner_of_shop.JPG corner of my shop an FMES is under the table under the silver foam insulation box http://www.volcanbaru.com/fmes/Electronics_stack.JPG Dave elelctronics, the schematics and board files are available. The LED make setup a snap. http://www.volcanbaru.com/fmes/fmes_angel.JPG new FMES on the work table http://www.volcanbaru.com/fmes/fmes_angel2.JPG more of the above http://www.volcanbaru.com/fmes/fmes_base.JPG Dave style base http://www.volcanbaru.com/fmes/fmes_parts.JPG Early FMES, they work real well and is made from hardware store stuff http://www.volcanbaru.com/fmes/fms65.JPG an FMES in my vault http://www.volcanbaru.com/fmes/internal_and_external_electrodes.JPG Electrode parts before assembly http://www.volcanbaru.com/fmes/mexico_1_4.jpg mexico jan 4 on early fmes 60 minute time scale http://www.volcanbaru.com/fmes/Pinch_valve.JPG pinch valve, no longer used http://www.volcanbaru.com/fmes/sandwich.jpg Sandwich Island quake and a little local event on first line and a bit of noise on the second line. 120 minutes per line http://www.volcanbaru.com/fmes/Transducer_detail.JPG Transducer parts http://www.volcanbaru.com/fmes/Transducer_end.JPG Assembles transducer http://www.volcanbaru.com/fmes/transducer_detai3.JPG more transducer details http://www.volcanbaru.com/fmes/transducer_detail2.JPG more detail http://www.volcanbaru.com/fmes/tube_valve.JPG restriction detail http://www.volcanbaru.com/fmes/two_traces.jpg my broadband top lineand the FMES on the bottom line http://www.volcanbaru.com/fmes/vault2.JPG BB and FMES in my vault I am sure that there are hundreds of ways to configure an FMES, these just a few. I will be on vacation for the next three weeks (starting the 28th) but will be but will try to check my mail and will be glad to help anyone get one of these going. I am sure that Dave will help also. I will try to write a bit more after dinner. I talked to Dave and he is going to pipe in. Angel __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Calif--100th Anniversary From: "Connie and Jim Lehman" lehmancj@........... Date: Sat, 22 Apr 2006 22:39:48 -0400 Thanks Steve, Larry, Richard, John & Jan for arranging the informal PSN = get-together Tues. eve. We enjoyed several field trips as well as = several technical sessions during the week. Best wishes in keeping the = PSN vision alive and well.. Jim=20
Thanks Steve, Larry, Richard, = John &=20 Jan for arranging the informal PSN get-together Tues. eve.  We = enjoyed=20 several field trips as well as several technical sessions during the = week. =20 Best wishes in keeping the PSN vision alive and well..   Jim=20
In a message dated 23/04/2006, lcochrane@.............. writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000=20 size=3D2>>     Like the VM channel (LCTST) my LC8 channe= l is=20 pretty much the raw
>     data from the pickup=20 except there are two 60 second high-pass filters in the
> =20    signal path. My LC3 channel, the integrated output, should ha= ve a=20 velocity >response from about 1 second, the period of the pendulum= , to=20 about 50 seconds. I
>     have not made any changes t= o my=20 SG sensor for many years so the
>     value of the=20 integrator parts should be the same.
>
>     T= he=20 circuit at http://psn.quake.net/sg-schm.gif shows a 100 K Ohm
> inp= ut=20 resistor, a 470 K Ohm feedback resistor and a 2 mu F parallel
>=20 capacitor. This RC combination rolls off at a period of only 5.9 seconds=20
> - a factor of 10 less than we want.
>     Do= you=20 still use a 4.7 M Ohm feedback resistor, like in your
> previous=20 circuit at http://psn.quake.net/sgproc.gif ?
>    =20 Moreover, there does not seem to be a 1 sec low pass circuit to
>=20 produce a velocity response?

I still use a 4.7M feedback resistor a= nd a=20 2.2UF cap. There is a 60 second high-pass filter before the integrator to=20 limit the low frequencies and DC offset going into
the=20 integrator.
I appreciated that you had split the integrator= =20 circuit over the two opamps. One way of improving the performance a bit is t= o=20 use a two pole high pass filter on the input, instead of the single pole. It= =20 gives a much sharper cutoff.
I also question whether we really do need a 60=20= sec=20 response for general purposes? I suspect that 30 to 40 sec would be quite=20 adequate?
The other problem with the S/G circuit is that=20= you=20 do need to make an effort to limit the system noise, since the low frequency= =20 gains need to be quite high. This is a suitable application for CAZ=20 opamps.
I note that to give a velocity signal you need=20= to=20 differentiate the S/G output from 1 to 10 Hz. You would probably be able to=20 use four instead of six stages of 10 Hz LP filter if you did this?= A=20 3.3 mu F capacitor in series with the 50 K Ohm variable input resistor to th= e HF=20 channel should do this quite well.
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000=20 size=3D2>>     Note that it is usually possible to lengt= hen=20 the period using
> digital processing - if there is sufficient sign= al=20 resolution, as seems
> likely with the VM 24 bit ADC. However, doin= g=20 this to a displacement
> signal is likely to give rather large=20 amplitudes at the low frequencies.
> Maybe the VM displacement sign= al=20 could be converted into a velocity signal?

Remember that a pendulum= =20 with a displacement pickup will act as an accelerometer below the period o= f=20 the pendulum, so both the SG and the new VM sensor are recording accelerat= ion=20 for teleseismic events. The integrator, in the SG sensor electronics (my L= C3=20 channel), should be producing a velocity signal. I should be able to do th= e=20 same thing in WinSDR by digitally integrating the acceleration signal from= the=20 VM sensor.
Great!
Can you also differentiate the VM signals above= the=20 1 Hz pendulum frequency to give a velocity signal from 1 to 10 Hz?

In the S/G Construction Notes the 'photos of my= SG=20 sensors' and the first 'photos of my sensors here' both have broken=20 links.
The link to Arie Verveer's S/G seismometers no=20 longer works. Could you put his photos on your website, please?

Regards,

Chris Chapman
are these related to a storm front an the spikes are lightning "up" strike and related "down" strike or thunder? What was the weather like, this day?
cheers
col lynam
Brisbane, Australia

David Saum wrote:
I am still debugging my infrasound
detector, but I have been picking up
some interesting detections recently:

Here is a 24 hour data plot from this morning
http://www.infiltec.com/Infrasound@...............
with an interesting data spike at 10:35UT (6:35AM local).

Here is a blow up of the data showing that it is
actually a small spike followed about 3 seconds
later by a larger spike.
http://www.infiltec.com/Infrasound@................

And here is a blow up of the two similar detections
at 1:30 and 1:35UT (9:30 and 9:35PM local)
http://www.infiltec.com/Infrasound@................

I have been picking up 0-10 similar detections per day,
generally with the first spike smaller than the second,
the spacing is about 3 seconds (all less than 10 seconds)
and occasionally there is a third small spike about 3 seconds
after the large spike.

My infrasound monitor is on my 4th floor deck, with
no spatial averaging.  I am located in the Washington, DC
metro area about 10 miles from Reagan airport and 10
miles from major construction on the Springfield, VA
I95 interchange and the Potomac bridge project.

Anyone have any idea what these signals could
be coming from?

System info:

Exterior of microbarograph with serial cable:
http://www.infiltec.com/Infrasound@.................
Interior of microbarograph:
http://www.infiltec.com/Infrasound@.................
PCB removed from box
http://www.infiltec.com/Infrasound@.................
PCB and high-pass pneumatic filter removed from box:
http://www.infiltec.com/Infrasound@.................

System Bandpass: 0.01 to 4 Hz.
High-Pass filter: ~100 sec or 0.01 Hz using volume/capillary tube.
Low pass filter: 4 Hz anti-alias, 8 pole Bessel filter (MAX4701)
Differential pressure sensor: silicon, bridge type, 1"wc (DUXL01D)
Pres Resolution: ~0.004 Pa - possibly lower depending offsets
Range: +/- 120 Pa (32768 times pressure resolution)
Amp: instrumentation,1000x,single supply,micropower,RTR out(INA122P)
Power: ~2ma 5VDC, derived from PC serial port, no external power supply
Regulator: 5VDC, low dropout micropower, precision (LP2950-5.0)
Amplifier Reference Voltage: 2.5VDC fixed, precision reference (LT1004-2.5)
Microprocessor: 4mhz, onboard 16 bit ADC and serial I/O (PIC14000)
Firmware: ADC sampling at ~35 SPS, zero drift tracking ~5 min TC.
Enclosure: diecast aluminum box for shielding (Hammond 1590P)
Serial Out: RS232, 9600 baud, 8N1, ASCII records, -32767 to +32767
Wind Spatial Averaging: array of micro-perforated garden tubing
Data Log/Display: freeware PC AMASEIS seismic log/analysis software

Dave

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No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.1.385 / Virus Database: 268.4.5/322 - Release Date: 22/04/2006 Subject: Re: interesting infrasound detections? From: ChrisAtUpw@....... Date: Mon, 24 Apr 2006 21:57:16 EDT In a message dated 24/04/2006, DSaum@............ writes: I am still debugging my infrasound detector, but I have been picking up some interesting detections recently: Here is a 24 hour data plot from this morning _http://www.infiltec.com/Infrasound@................ (http://www.infiltec.com/Infrasound@................ with an interesting data spike at 10:35UT (6:35AM local). Here is a blow up of the data showing that it is actually a small spike followed about 3 seconds later by a larger spike. _http://www.infiltec.com/Infrasound@................. (http://www.infiltec.com/Infrasound@................. Hi Dave, I suggest that you seal up the air inlet tube and run the apparatus for 24 hrs to see if it is picking up electrical interference - and what sort? I note that you are using the computer power supplies - they are not always well filtered. The signals, although clear, are not very large. Do the times correspond to switching times of the building temperature control or ventilation systems? Maybe switch them on and off to see if you get any peaks? Do you have a fridge, or a water cooler on the same circuit? Could this be power switching on the grid? My lights do flicker occasionally. Regards, Chris Chapman
In a message dated 24/04/2006, DSaum@............ writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>I am=20 still debugging my infrasound detector, but I have been picking up
some= =20 interesting detections recently:

Here is a 24 hour data plot from t= his=20 morning http://www.inf= iltec.com/Infrasound@...............
with=20 an interesting data spike at 10:35UT (6:35AM local).

Here is a blow= up=20 of the data showing that it is actually a small spike followed about 3 sec= onds=20 later by a larger spike.
http://www.in= filtec.com/Infrasound@................=20
Hi Dave,

I suggest that you seal up the air inlet t= ube=20 and run the apparatus for 24 hrs to see if it is picking up electrical=20 interference - and what sort? I note that you are using the computer power=20 supplies - they are not always well filtered. The signals, although cle= ar,=20 are not very large.
Do the times correspond to switching time= s of=20 the building temperature control or ventilation systems? Maybe switch t= hem=20 on and off to see if you get any peaks? Do you have a fridge, or a wate= r=20 cooler on the same circuit? Could this be power switching on the grid? My li= ghts=20 do flicker occasionally.

Regards,

Chris Chapman
Subject: Re: interesting infrasound detections? From: "David Saum" DSaum@............ Date: Tue, 25 Apr 2006 07:28:00 -0400 Mystery solved! Unfortunately the source was me. The initial small pulse is my front door opening, and the second larger pulse about 3 seconds later was my front door closing. I was able to reproduce the phenomena at will. Due to warmer weather, a window onto my deck had recently been opened about an inch, and the pulsing of the air from the house due to the front door opening and closing was enough to cause the spikes on my microbarograph. The microbarograph is about 10 feet away from the window, but changing its position does not seem to make much difference in the size of the spikes. My deck is enclosed on all but one side (dim ~20'x10'x10') so all the air in the deck volume seems to be getting pulsed by the window opening. The simplest solution seems to be closing the window, but longer term I need to set up a spatial averaging array of soaker hoses in a field. Sorry for the false alarm. No little green men this time. :( Dave __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: interesting infrasound detections? From: Barry Lotz barry_lotz@............. Date: Tue, 25 Apr 2006 05:39:14 -0700 (PDT) Hi David Maybe it could be some component of the building moving during heating and cooling of the day. Sunny during events? Regard Barry David Saum wrote: I am still debugging my infrasound detector, but I have been picking up some interesting detections recently: Here is a 24 hour data plot from this morning http://www.infiltec.com/Infrasound@............... with an interesting data spike at 10:35UT (6:35AM local). Here is a blow up of the data showing that it is actually a small spike followed about 3 seconds later by a larger spike. http://www.infiltec.com/Infrasound@................ And here is a blow up of the two similar detections at 1:30 and 1:35UT (9:30 and 9:35PM local) http://www.infiltec.com/Infrasound@................ I have been picking up 0-10 similar detections per day, generally with the first spike smaller than the second, the spacing is about 3 seconds (all less than 10 seconds) and occasionally there is a third small spike about 3 seconds after the large spike. My infrasound monitor is on my 4th floor deck, with no spatial averaging. I am located in the Washington, DC metro area about 10 miles from Reagan airport and 10 miles from major construction on the Springfield, VA I95 interchange and the Potomac bridge project. Anyone have any idea what these signals could be coming from? System info: Exterior of microbarograph with serial cable: http://www.infiltec.com/Infrasound@................. Interior of microbarograph: http://www.infiltec.com/Infrasound@................. PCB removed from box http://www.infiltec.com/Infrasound@................. PCB and high-pass pneumatic filter removed from box: http://www.infiltec.com/Infrasound@................. System Bandpass: 0.01 to 4 Hz. High-Pass filter: ~100 sec or 0.01 Hz using volume/capillary tube. Low pass filter: 4 Hz anti-alias, 8 pole Bessel filter (MAX4701) Differential pressure sensor: silicon, bridge type, 1"wc (DUXL01D) Pres Resolution: ~0.004 Pa - possibly lower depending offsets Range: +/- 120 Pa (32768 times pressure resolution) Amp: instrumentation,1000x,single supply,micropower,RTR out(INA122P) Power: ~2ma 5VDC, derived from PC serial port, no external power supply Regulator: 5VDC, low dropout micropower, precision (LP2950-5.0) Amplifier Reference Voltage: 2.5VDC fixed, precision reference (LT1004-2.5) Microprocessor: 4mhz, onboard 16 bit ADC and serial I/O (PIC14000) Firmware: ADC sampling at ~35 SPS, zero drift tracking ~5 min TC. Enclosure: diecast aluminum box for shielding (Hammond 1590P) Serial Out: RS232, 9600 baud, 8N1, ASCII records, -32767 to +32767 Wind Spatial Averaging: array of micro-perforated garden tubing Data Log/Display: freeware PC AMASEIS seismic log/analysis software Dave
Hi David
Maybe it could be some component of the building moving during heating and cooling of the day. Sunny during events?
Regard
Barry

David Saum <DSaum@............> wrote:
I am still debugging my infrasound
detector, but I have been picking up
some interesting detections recently:

Here is a 24 hour data plot from this morning
http://www.infiltec.com/Infrasound@...............
with an interesting data spike at 10:35UT (6:35AM local).

Here is a blow up of the data showing that it is
actually a small spike followed about 3 seconds
later by a larger spike.
http://www.infiltec.com/Infrasound@................

And here is a blow up of the two similar detections
at 1:30 and 1:35UT (9:30 and 9:35PM local)
http://www.infiltec.com/Infrasound@................

I have been picking up 0-10 similar detections per day,
generally with the first spike smaller than the second,
the spacing is about 3 seconds (all less than 10 seconds)
and occasionally there is a third small spike about 3 seconds
after the large spike.

My infrasound monitor is on my 4th floor deck, with
no spatial averaging. I am located in the Washington, DC
metro area about 10 miles from Reagan airport and 10
miles from major construction on the Springfield, VA
I95 interchange and the Potomac bridge project.

Anyone have any idea what these signals could
be coming from?

System info:

Exterior of microbarograph with serial cable:
http://www.infiltec.com/Infrasound@.................
Interior of microbarograph:
http://www.infiltec.com/Infrasound@.................
PCB removed from box
http://www.infiltec.com/Infrasound@.................
PCB and high-pass pneumatic filter removed from box:
http://www.infiltec.com/Infrasound@.................

System Bandpass: 0.01 to 4 Hz.
High-Pass filter: ~100 sec or 0.01 Hz using volume/capillary tube.
Low pass filter: 4 Hz anti-alias, 8 pole Bessel filter (MAX4701)
Differential pressure sensor: silicon, bridge type, 1"wc (DUXL01D)
Pres Resolution: ~0.004 Pa - possibly lower depending offsets
Range: +/- 120 Pa (32768 times pressure resolution)
Amp: instrumentation,1000x,single supply,micropower,RTR out(INA122P)
Power: ~2ma 5VDC, derived from PC serial port, no external power supply
Regulator: 5VDC, low dropout micropower, precision (LP2950-5.0)
Amplifier Reference Voltage: 2.5VDC fixed, precision reference (LT1004-2.5)
Microprocessor: 4mhz, onboard 16 bit ADC and serial I/O (PIC14000)
Firmware: ADC sampling at ~35 SPS, zero drift tracking ~5 min TC.
Enclosure: diecast aluminum box for shielding (Hammond 1590P)
Serial Out: RS232, 9600 baud, 8N1, ASCII records, -32767 to +32767
Wind Spatial Averaging: array of micro-perforated garden tubing
Data Log/Display: freeware PC AMASEIS seismic log/analysis software

Dave

arising out of the edge of the inner crater.  Regular news sources cla= im the slab is as big
as a football field, and is rising upward at the rate of 4-5 feet a day rec= ently!  The crater
itself is ~ 2 miles in diameter.

http://vulcan.wr.usgs.gov/Volcanoes/MSH/Images/MSH04/framework.html

Subject: RE: Mt. St. Helens Volcano and its strange rising slab or "fin" shaped material From: "Kareem" system98765@............. Date: Sun, 7 May 2006 16:21:03 -0700 wow. seems like those days prior to may 18, 1980. (4-5 feet a day). _____ From: psn-l-request@.............. [mailto:psn-l-request@............... On Behalf Of meredith lamb Sent: Saturday, May 06, 2006 9:06 PM To: psn-l@.............. Subject: Mt. St. Helens Volcano and its strange rising slab or "fin" shaped material Heres a interesting URL with multiple pictures, showing a giant slab or fin shaped material arising out of the edge of the inner crater. Regular news sources claim the slab is as big as a football field, and is rising upward at the rate of 4-5 feet a day recently! The crater itself is ~ 2 miles in diameter. http://vulcan.wr.usgs.gov/Volcanoes/MSH/Images/MSH04/framework.html
wow.

seems like those days prior to may 18, 1980. = (4-5 feet a=20 day).

From: psn-l-request@................. [mailto:psn-l-request@............... On Behalf Of meredith=20 lamb
Sent: Saturday, May 06, 2006 9:06 PM
To:=20 psn-l@..............
Subject: Mt. St. Helens Volcano and its = strange=20 rising slab or "fin" shaped material

Heres a interesting URL with multiple pictures, showing a = giant slab=20 or fin shaped material
arising out of the edge of the inner = crater. =20 Regular news sources claim the slab is as big
as a football field, = and is=20 rising upward at the rate of 4-5 feet a day recently!  The = crater
itself=20 is ~ 2 miles in diameter.

http://vulcan.wr.usgs.gov/Volcanoes/MSH/Images/MSH04/framework.html

Subject: Re: Mt. St. Helens Volcano and its strange rising slab or "fin" From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Sun, 07 May 2006 23:43:51 +0000 Hi all This slab that is coming out of Mt. St. Helens volcano crater is really intresting. It looks like it is coming from deep underground. If it survies the formation of a new lava dome it is going to give huge amount of info about inner structure of Mt. St. Helens. This slab might also be really, really old if it is coming from deep underground. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Mt. St. Helens Volcano and its strange rising slab or "fin"shaped material From: "Geoffrey" gmvoeth@........... Date: Sun, 7 May 2006 22:53:13 -0700 You guys never saw that movie "Monolith Monsters" ----- Original Message ----- From: "Jón Frímann" To: Sent: Sunday, May 07, 2006 4:43 PM Subject: Re: Mt. St. Helens Volcano and its strange rising slab or "fin"shaped material > Hi all > > This slab that is coming out of Mt. St. Helens volcano crater is really > intresting. It looks like it is coming from deep underground. If it > survies the formation of a new lava dome it is going to give huge amount > of info about inner structure of Mt. St. Helens. This slab might also be > really, really old if it is coming from deep underground. > > Regards. > -- > Jón Frímann > http://www.jonfr.com > http://www.simnet.is/jonfr500/earthquake/ > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: eBay seismometer listing From: Bobhelenmcclure@....... Date: Mon, 8 May 2006 22:29:03 EDT Seismometer GeoSpace Geo-Space Seismology Earthquake Item number: 7617763900 Model HS-????/3D Apparently a 3 axis sensor, maybe of HS-10 type? Bob
Seismometer GeoSpace Geo-Space Seismology Earthquake
Item number: 7617763900
Model HS-????/3D

Apparently a 3 axis sensor, maybe of HS-10 type?

Bob
Subject: Use of Cat-5 cable when connecting a geophone From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Wed, 10 May 2006 04:07:09 +0000 Hi all I use cat-5 network cable to connect my geophone to my winsdr amplifer board. So far my experience with that type of cable has been good. Since it appears not to pickup alot of noise from it's closest evroment. Also the signal loss seems to be minimal, even if the cable is some meters in lengh. I don't know if anyone else is using cat-5. But comment on this usage of cat-5 are what i need to know if this is a good thing or not. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Use of Cat-5 cable when connecting a geophone From: Jim E ODonell jimo17@........ Date: Tue, 9 May 2006 21:37:08 -0700 Hi Jon- I have used it for years in Down Hole (3 geophones down the hole) seismic surveys- Since it has twisted pairs this reduces the noise pickup and it is cheap. It is #24 solid wire which breaks real easy if it gets moved a lot. But once in place it should do fine....Jim Jim O'Donnell Geological/Geophysical Consultant GEOTECHNICAL APPLICATIONS On Wed, 10 May 2006 04:07:09 +0000 =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= writes: > Hi all > > I use cat-5 network cable to connect my geophone to my winsdr > amplifer > board. So far my experience with that type of cable has been good. > Since > it appears not to pickup alot of noise from it's closest evroment. > Also > the signal loss seems to be minimal, even if the cable is some > meters in > lengh. > > I don't know if anyone else is using cat-5. But comment on this > usage of > cat-5 are what i need to know if this is a good thing or not. > > Regards. > -- > Jón Frímann > http://www.jonfr.com > http://www.simnet.is/jonfr500/earthquake/ > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > >
Hi Jon-
I have used it for years in Down Hole (3 geophones down the hole) = seismic=20 surveys-  Since it has twisted pairs this reduces the noise pickup and= it=20 is cheap.  It is #24 solid wire which breaks real easy if it gets = moved a=20 lot.   But once in place it should do fine....Jim

Jim O'Donnell    =20
Geological/Geophysical Consultant
GEOTECHNICAL APPLICATIONS
On Wed, 10 May 2006 04:07:09 +0000 =3D?ISO-8859-1?Q?J=3DF3n_Fr=3D= EDmann?=3D <jonfr500@.........> writes:
&= gt; Hi=20 all
>
> I use cat-5 network cable to connect my geophone to my= =20 winsdr
> amplifer
> board. So far my experience with that type= of=20 cable has been good.
> Since
> it appears not to pickup alot = of=20 noise from it's closest evroment.
> Also
> the signal loss = seems to=20 be minimal, even if the cable is some
> meters in
> lengh.
= >=20
> I don't know if anyone else is using cat-5. But comment on this=20
> usage of
> cat-5 are what i need to know if this is a good = thing=20 or not.
>
> Regards.
> --
> J=F3n Fr=EDmann
&= gt; http://www.jonfr.com
> http://www.simnet.is/= jonfr500/earthquake/
>=20
> __________________________________________________________
>= =20
> Public Seismic Network Mailing List (PSN-L)
>
> To = leave=20 this list email PSN-L-REQUEST@.............. with=20
> the body of the message (first line only): unsubscribe
>
>

Subject: Seismic clipping levels From: Brett Nordgren Brett3kg@............. Date: Mon, 15 May 2006 10:15:51 -0400 To all, There is a relatively new USGS report that gives the maximum expected ground motion at 87 continental US locations (the UNSS backbone stations) for the purpose of testing instrument clipping levels. Clipping levels and max ground motion is a subject that fairly regularly comes up on PSN-L and this data may help provide some good guidance. The report can be downloaded from http://pubs.usgs.gov/of/2005/1437/ To come up with the data the authors had to do some extremely complex statistical work which I am currently trying to understand, but it's clear that coming up with good data isn't easy. Their numbers give the ground motion levels that had a 10% chance of being exceeded in a time period of 30 years. That's probably way too conservative for amateur work; better would probably be 10% in 1 year or even 50% in 1 year. I'm trying to understand their process well enough to be able to manipulate the raw data to get those, but I still have a lot to learn. I've put the results in an Excel file http://bnordgren.org/seismo/station_pgv.xls (164kb) in a form that includes spectrum charts, which should be useful to compare with individual instrument clipping levels. And the general process should be useful in evaluating sites anywhere in the world. If anyone who really understands this stuff can point me to resources relating to the statistical methods and raw data sources, I would be most grateful. Regards, Brett __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: neis web page??? From: "Connie and Jim Lehman" lehmancj@........... Date: Mon, 15 May 2006 20:36:16 -0400 PSN folks--for months/years I have had the National Earthquake = Information Service Web site bookmarked in for easy access to current = seismic events. In the past week or so a strange NEIS page comes up = with no information. Has there been an address change?? I would think = the service would continue with excellent public information as it has = in the past. Any ideas?? Jim Lehman =20
PSN folks--for months/years I have had = the National=20 Earthquake Information Service Web site bookmarked in for easy access to = current=20 seismic events.  In the past week or so a strange NEIS page = comes up=20 with no information.  Has there been an address change??  I = would=20 think the service would continue with excellent public information as it = has in=20 the past.   Any = ideas??        Jim=20 Lehman

The earthquake wave that i=20= did record does not fit predicted p and s arrival
time.

Hi Jon,

Download the time / travel chart! Y= ou are 160 deg long and 100 deg lat away and you are using geophones.

Regards,

Chris Chapman
Many thanks to John, Bob, Thomas & = Geoffrey for=20 bringing me up to date on the changes in the NEIS page.  I am = bookmarked ok=20 again.
I remember the not so old days = when we=20 waited for the bi-weekly or monthly bulletins to arrive by mail ...or at = times=20 place a long distance call to the Colorado Center and talk directly to = Waverly=20 Persons or one of his associates---they were always patient and=20 helpful.           = ;   =20 Jim Lehman
Subject: hammer seismic interpretation From: james fisher kd6iwd@......... Date: Tue, 16 May 2006 18:37:54 -0700 (PDT) Hi, I have a question about interpretation of seismic data for the group. I have built a hammer seismic system which incorporates a memory scope. I can hammer the ground any number of times and sum the returned signal. This gives vastly increased sensitivity and immunity to noise. can anyone suggest sources of information on how to measure the depth to bedrock with this type of device? I have used the sound card on a pc and piezo disks to detect and trigger the data collection. Best Regards jim __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: hammer seismic interpretation From: ChrisAtUpw@....... Date: Tue, 16 May 2006 23:19:15 EDT In a message dated 17/05/06, kd6iwd@......... writes: > I have built a hammer seismic system which incorporates a memory scope. I > can hammer the ground any number of times and sum the returned signal. This > gives vastly increased sensitivity and immunity to noise. Can anyone suggest > sources of information on how to measure the depth to bedrock with this type > of device? Hi Jim, Can you use two high frequency piezo disks with a light centre load and a summing amplifier? You may have to damp the disks with polyurethane foam. Put one disk close to the hammer plate and the other several feet away. The timing in between the two disks will ~measure the ground velocity and then you look for reflections. But you need to reckon on 3 to 5 km / sec for the ground waves - you are likely to be measuring time intervals in milliseconds, if not microseconds. I think that commercial type equipment will probably use a variable gain amplifier (transconductance type) triggered by the initial pulse. The reflected signal drops off at about the 4th power of the depth. By separating the two sensors, you can put a higher gain on the remote one. This might be an application for silicon accelerometers? They may have a higher natural frequency than piezo disks. Do you have any estimate of the depth to the bedrock? Regards, Chris Chapman In a message=20= dated 17/05/06, kd6iwd@......... writes:

I have built a hammer seism= ic system which incorporates a memory scope. I
can hammer the ground any number of times and sum the returned signal. T= his gives vastly increased sensitivity and immunity to noise. Can anyone sug= gest
sources of information on how to measure the depth to bedrock with this=20= type of device?

Hi Jim,

Can you use two high frequency piez= o disks with a light centre load and a summing amplifier? You may have to da= mp the disks with polyurethane foam. Put one disk close to the hammer plate=20= and the other several feet away. The timing in between the two disks will ~m= easure the ground velocity and then you look for reflections. But you need t= o reckon on 3 to 5 km / sec for the ground waves - you are likely to be meas= uring time intervals in milliseconds, if not microseconds. I think that comm= ercial type equipment will probably use a variable gain amplifier (transcond= uctance type) triggered by the initial pulse. The reflected signal drops off= at about the 4th power of the depth. By separating the two sensors, you can= put a higher gain on the remote one.=20
This might be an application for si= licon accelerometers? They may have a higher natural frequency than piezo di= sks. Do you have any estimate of the depth to the bedrock?

Regards,

Chris Chapman
Subject: Re: My Kermadec Islands Region earthquake recording From: ChrisAtUpw@....... Date: Tue, 16 May 2006 23:26:19 EDT In a message dated 17/05/06, jonfr500@......... writes: > But what surprices me the most is the fact i did actually detect this > earthquake, at this range. Even if the p and s waves are strange. I > didn't think this was possible with my geophone. Hi Jon, With large quakes you can also pick up locally generated noise. The geophone response falls off below 4.5 Hz as f^2 - it does not go to zero. Do a FFT and see what the signal peak frequencies were? Regards, Chris Chapman In a message=20= dated 17/05/06, jonfr500@......... writes:

But what surprices me the m= ost is the fact i did actually detect this
earthquake, at this range. Even if the p and s waves are strange. I
didn't think this was possible with my geophone.

Hi Jon,

With large quakes you can also pick= up locally generated noise. The geophone response falls off below 4.5 Hz as= f^2 - it does not go to zero. Do a FFT and see what the signal peak frequen= cies were?

Regards,

Chris Chapman

I
did clean everything abov= e 1Hz out of the recording to actually see
the signal. I did the same thing with the eastern siberia earthquake in
April, that I detected. Even if the response falls flat below 2Hz,
there seems to be surprising lot of data below 2Hz.

Hi Jon,

The geophone response will fall to=20= 1/5 at 2Hz, to 1/20 at 1 Hz and to 1/100 at 0.45 Hz. It does not 'fall flat'= , more like it takes a 'nose dive'!
If you get strong enough seismic si= gnals you will certainly see them to below 1 Hz. You may also see locally ge= nerated noise as the result of the quake.
The geophone compensator circuits a= re designed to go from the 20 / 10 Hz of the low pass filter down to 0.45 Hz= , flat to velocity. You do get some additional noise, but it is quite small.= This does enable you to detect teleseismic P and S waves with a 4.5 Hz geop= hone.

Regards,

Chris Chapman
In a message dated 21/05/2006, jonfr500@......... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>Is there=20 a software out there that can draw a picture of what earthquake
wave pa= sses=20 through? Something like a sonar type of software. I am not
sure of the=20= this=20 is exactly called in english. I will try to clear this
up if this can't= be=20 understand in this email.
Hi Jon,

There are world wide seismic demonstration prog= rams=20 showing how quake signals propagate and interact at http:/= /web.ics.purdue.edu/~braile/edumod/svintro/svintro.htm
For local earthquakes, reflection / refraction=20 signals and seismic prospecting you may need arrays of sensors and= =20 quite elaborate data analysis programs.

Regards,

Chris Chapman
In a message dated 22/05/2006, jonfr500@......... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>I more=20 often then not I get a one single line spike into my earthquake recording,= =20 those spikes can be seen on my online tremor plots. The wire that i use to= =20 connect to the amplifer board is near alot of electronic hardware, tv, vcr= ,=20 sky digital box, subscription tv box for local channel, tvo adsl tv decode= r=20 box.
Hi Jon,

One of the common causes of spikes may be the=20 inductive motor of your refrigerator switching on and off. It is likely= to=20 effect the whole of the house wiring and can be difficult to=20 eliminate. Try switching your fridge on and off to see if there are spikes?=20
You can buy the Electrolux type fridge which ju= st=20 has an electric / gas heater to drive it - no motor.

Regards,

Chris Chapman
In a message dated 22/05/2006, apsn@........... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>I need=20 to move my GPS antenna (Oncore GPS for WinSDR timing) to a
location su= ch=20 that I need to add 50' of coax.  What do you suggest
for coax and= =20 where can I find adapters for that tiny right-angle MMCX=20
connector?
Hi Bob,

Do you have to extend the aerial co-ax at all?=20= Can=20 you not site the aerial + receiver remotely and extend the cable connecting=20= it=20 to the computer?
The problems of RS232 connection are likely to=20= be=20 minimal up to 50 m. Hi grade low loss UHF cable tends to be expensive. I not= e=20 that the web suppliers tend only to sell cable by the 100ft minimum.

Regards,

Chris Chapman

I'm probably a bit closer, Russia just being a short hop over the North Pole from here, sort of.

Cheers

Ian

George Bush wrote:
Ian-

I am glad you at least got the second one! I assume that the reason that I
didn't was that it was masked my the ocean noise due to my location.

At 07:01 PM 5/22/06 +0100, you wrote:

The P wave of the first one jammed my Lehman!  When I fixed it an hour
later I got the remains of it.  :-(
http://www.iasmith.com/realtime.htm

I did pick up the second one but at a lower signal strength.

Cheers

Ian Smith

George
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Subject: Re: GPS location avarge From: Larry Cochrane lcochrane@.............. Date: Wed, 24 May 2006 20:19:49 -0700 Hi Jón, Probably a few hours is all that is needed but I would let WinSDR average the data for a day or two. Regards, Larry Cochrane Redwood City, PSN Jón Frímann wrote: > Hi all > > I got my garmin gps antenna today. How many days do i have to keep it on > "GPS Location" to get farly accure location for WinSDR ? > > Regards. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: spike problem From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Fri, 26 May 2006 12:24:39 +0000 Hi all Is there any way for me to reduse the spike problem that I am having ? I can draw up the current setup to explain the problem if needed. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: spike problem From: ChrisAtUpw@....... Date: Fri, 26 May 2006 11:35:47 EDT In a message dated 26/05/06, jonfr500@......... writes: > Is there any way for me to reduce the spike problem that I am having? > I can draw up the current setup to explain the problem if needed. Hi Jon, How many spikes do you see per hour and are they a ~single pulse or several? What sizes are they? Is the size very variable? Are there any particular times over 24 hrs when the interference is more severe? Spikes on a quake trace are often due to pulses on the electricity supply in the house. Refrigerators which have an electric motor can put large spikes on the system as they turn on and off. If you have a fridge of this type, note when it turns on and off - maybe also try switching it with a wall socket switch - and look for spikes on the trace. Do you have electric heating in the house controlled by time clocks / thermostats? Since you live in a block of houses, you may also pick up local interference from other users. You can also get large spikes on the electricity supply if there are any 'industrial' users nearby. Large electric motors and electric welding are common sources within several km. They may also be due to switching between electricity generating plant and this can effect wide areas. It is often observed as a momentary dimming of electric light bulbs and the momentary failure of 1 to 2 m long strip light tubes. The normal method is to provide protection against transient spikes with a filter on the supply system and to provide large electrolytic storage capacitors on your power supplies. This enables the amplifier rail voltages to remain constant during a momentary power failure. Do you have house power wiring with three of just two connecting pins, and what voltage is it? You can also buy 'uninterruptable power supplies' for computers and similar low power equipment. These have an auxiliary 12/24 V backup lead acid battery which keeps the systems running during short power failures. Switch over time is about 1/2 a supply power cycle, 1/100 or 1/120 second. They may have a data link to the computer to enable it to save data / close down automatically. What sort of power supplies are you using for your amplifiers and are the common 0 V rails on amplifier boards effectively earthed at the signal input pins? Do you get much lightning? Regards, Chris Chapman In a message=20= dated 26/05/06, jonfr500@......... writes:

Is there any way for me to=20= reduce the spike problem that I am having?
I can draw up the current setup to explain the problem if needed.
=

Hi Jon,=20

How many spikes do you see per hour= and are they a ~single pulse or several?  What sizes are they? Is the=20= size very variable? Are there any particular times over 24 hrs when the inte= rference is more severe?

Spikes on a quake trace are often d= ue to pulses on the electricity supply in the house. Refrigerators which hav= e an electric motor can put large spikes on the system as they turn on and o= ff. If you have a fridge of this type, note when it turns on and off - maybe= also try switching it with a wall socket switch - and look for spikes on th= e trace. Do you have electric heating in the house controlled by time clocks= / thermostats? Since you live in a block of houses, you may also pick up lo= cal interference from other users.=20

You can also get large spikes on th= e electricity supply if there are any 'industrial' users nearby. Large elect= ric motors and electric welding are common sources within several km.

They may also be due to switching b= etween electricity generating plant and this can effect wide areas. It is of= ten observed as a momentary dimming of electric light bulbs and the momentar= y failure of 1 to 2 m long strip light tubes.

The normal method is to provide pro= tection against transient spikes with a filter on the supply system and to p= rovide large electrolytic storage capacitors on your power supplies. This en= ables the amplifier rail voltages to remain constant during a momentary powe= r failure.

Do you have house power wiring with= three of just two connecting pins, and what voltage is it?

You can also buy 'uninterruptable p= ower supplies' for computers and similar low power equipment. These have an=20= auxiliary 12/24 V backup lead acid battery which keeps the systems running d= uring short power failures. Switch over time is about 1/2 a supply power cyc= le, 1/100 or 1/120 second. They may have a data link to the computer to enab= le it to save data / close down automatically.=20

What sort of power supplies are you= using for your amplifiers and are the common 0 V rails on amplifier boards=20= effectively earthed at the signal input pins?

Do you get much lightning?

Regards,

Chris Chapman
In a message dated 30/05/2006 13:28:28 GMT Daylight Time,=20 gmvoeth@........... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>When You=20 talk about any EQ could you please
include the Date Time UT in the text= of=20 your
letters ? I would like to be able to identify things
a year lat= er=20 and these web sites do not always
live that=20 long.
There was only one.

28-MAY-2006 13:23:29 74.09 13.53 5.2 10.0 NORWEGIAN=20 SEA
Subject: Recording from unknown source From: Roger Sparks rsparks@.......... Date: Tue, 30 May 2006 17:28:11 -0700 Hello All, I and* ELL SHZ UW : Ellensburg, WA* recorded an event, but none of the other Washington seismic stations on the web recorded it. I am wondering what it might be? My recording is at http://www.seismicnet.com/cgi-dos/makegif.exe?/quakes/0605/060530.165536.ebgz.psn The UW recording is at http://www.pnsn.org/WEBICORDER/PNSN/ELL_SHZ_UW.2006053012.html I do not know exactly where *ELL SHZ UW : Ellensburg, WA* is located but I believe it is 5 or more miles away. I wonder if it might be a meteor? Roger __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Recording from unknown source From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Wed, 31 May 2006 00:49:36 +0000 Hi This is really strange signal. Check this webpage for meteor info, http://www.spaceweather.com/ But earth is passing trugh a debre from the remains of the comet 73P/Schwassmann Wachmann 3. I don't have time to check this signal at the moment, I am going to try to check it tomorrow. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Recording from unknown source From: apsn apsn@........... Date: Tue, 30 May 2006 16:55:10 -0800 Roger, Your waveform, and that of station ELL, looks like a regional earthquake to me. regards, Bob Hammond PSN - Alaska http://apsn.awcable.com At 03:34 PM 5/30/2006, you wrote: >Hello All, > >I and* ELL SHZ UW : Ellensburg, WA* recorded an event, but none of >the other Washington seismic stations on the web recorded it. I am >wondering what it might be? > >My recording is at >http://www.seismicnet.com/cgi-dos/makegif.exe?/quakes/0605/060530.165536.ebgz.psn > >The UW recording is at >http://www.pnsn.org/WEBICORDER/PNSN/ELL_SHZ_UW.2006053012.html > >I do not know exactly where *ELL SHZ UW : Ellensburg, WA* is located >but I believe it is 5 or more miles away. > >I wonder if it might be a meteor? > >Roger >__________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email PSN-L-REQUEST@.............. with the body >of the message (first line only): unsubscribe >See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Recording from unknown source From: ChrisAtUpw@....... Date: Tue, 30 May 2006 21:07:28 EDT In a message dated 31/05/2006, rsparks@.......... writes: I and* ELL SHZ UW : Ellensburg, WA* recorded an event, but none of the other Washington seismic stations on the web recorded it. I am wondering what it might be? My recording is at http://www.seismicnet.com/cgi-dos/makegif.exe?/quakes/0605/ 060530.165536.ebgz.psn Hi Roger, If you look carefuly at the trace, there is hf noise for maybe 15 sec before the main signal, which itself lasts for maybe 40 sec. If it had been a meteor, I would have expected an impulse signal without any initial buildup and with little tail. This looks more like a large aircraft to me. Regards, Chris Chapman
In a message dated 31/05/2006, rsparks@.......... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>I and*=20 ELL SHZ UW : Ellensburg, WA* recorded an event, but none of the other=20 Washington seismic stations on the web recorded it. I am wondering what it= =20 might be?

My recording is at=20
http://www.seismicnet.com/cgi-dos/makegif.exe?/quakes/0605/060530.1655= 36.ebgz.psn
Hi Roger,

If you look carefuly at the trace, there is hf=20 noise for maybe 15 sec before the main signal, which itself lasts for maybe=20= 40=20 sec. If it had been a meteor, I would have expected an impulse signal withou= t=20 any initial buildup and with little tail. This looks more like a large aircr= aft=20 to me.

Regards,

Chris Chapman

If I understand this properly, it sounds like you do not have the outer braid / shield of your cable connected at either end.  If so, then it should be but only at one end, the amplifier.  Having said that, since the cable goes outside, you should consider using a lighning arrestor at the amp end, just in case you get a hit.

Hope that helps.

Ian

Jón Frímann wrote:
Hi

Did you connect up the shield (screen) of the cable to the ground of the Amp/Filter
board?

The two colored wire is connected to the amp board properly, the same
goes for the single colored one. This happens also with a cat-5 cable
that is not screened, I was using that before I got screened cable. The
sheld it self is not connected to anything, since I can't connect it to
the ground, at least I don't know how to connect it to the ground. Since
I don't see any connection for it. I know that the problem is not in the
amp board. There are capacitors inside the geophone, I think that thease
are capacitors. I can ground the shield of the cat-5 cable. If I get
some instructions on how to do it. I can also replace the capacitors if
I know what to buy and how to replace them. I know about good electronic
store in Iceland that sells this type of items.

This spike problem has been getting worse since I got the geophone, it
was not there in the early start. In the past 2 months it has been

Regards.

Subject: Re: spike problem From: "Geoffrey" gmvoeth@........... Date: Sun, 4 Jun 2006 05:56:30 -0700 When I was programming my own seismic receiver using the serial Com1 port on a typical PC I ran into a problem relating to timing and control of the serial communications that caused similar symptoms. The way I beat it was a long time ago and I never recorded it so I cant tell you what I did to beat it. I think I had to run the program under DOS only and not windows to solve the problem but I am not sure about that. It is so very important to write a proper error checking for any program using the serial ports or you get these funny glitches because something wrong has happened in the conversion or transfer of data resulting in an erroneous data giving you those glitches. That is everything I know about what those glitches might be. In my program I just check for any errors at all and count them so that I know if that is the problem if I get any glitches in my data. It is very difficult to include a proper error checking program. I think Windows is a time sharing thing and that will alone mess up the timing and control of asynchronous serial communications. Not certain about any of this but I no longer get these glitches or errors running under DOS in Windows 95. Sincerely; gmvoeth ----- Original Message ----- From: "Jón Frímann" To: Sent: Saturday, June 03, 2006 8:42 PM Subject: RE: spike problem > Hi Steve > > Yes, I have cordless telephone. But thease spikes happen even if the > phone is not ringing at all. > > Regards. > -- > Jón Frímann > http://www.jonfr.com > http://www.simnet.is/jonfr500/earthquake/ > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: spike problem From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Sun, 04 Jun 2006 16:46:25 +0000 Hi I have connected the shield in the cable to the ground. Trugh a heating oven (or how it is spelled / word over it) in the room, it uses hot water so it is ideal for this type of connection to the ground. That is going to elimiate the shield problem chargeing up, at least it I hope it does. The connection to the ground is farly good. There is paint on the heating oven, but I don't think that is a problem. Now I only have to fix the larger spikes. Or replace the capacitor that is possible leaking, this spikes happens on all the channels, so I am problay going to have to replace them all. If that can be done. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: spike problem From: ChrisAtUpw@....... Date: Sun, 4 Jun 2006 12:50:11 EDT In a message dated 03/06/2006, jonfr500@......... writes: The spike problem still exist Hi Jon, What length of cable in m are you using to connect the geophones to the amplifier board? Does the cat5 cable have a single bare wire inside the aluminised screen? It should have four tightly twisted pairs of insulated wires. Regards, Chris Chapman
In a message dated 03/06/2006, jonfr500@......... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>The=20 spike problem still exist
Hi Jon,

What length of cable in m are you using to conn= ect=20 the geophones to the amplifier board?

Does the cat5 cable have a single bare wire ins= ide=20 the aluminised screen? It should have four tightly twisted pairs of insulate= d=20 wires.

Regards,

Chris Chapman
Subject: Re: spike problem From: John Popelish jpopelish@........ Date: Sun, 04 Jun 2006 13:02:56 -0400 J=F3n Fr=EDmann wrote: > Hi >=20 > I have connected the shield in the cable to the ground. Trugh a heating= > oven (or how it is spelled / word over it) in the room, it uses hot > water so it is ideal for this type of connection to the ground. That is= > going to elimiate the shield problem chargeing up, at least it I hope i= t > does. The connection to the ground is farly good. There is paint on the= > heating oven, but I don't think that is a problem. >=20 > Now I only have to fix the larger spikes. Or replace the capacitor that= > is possible leaking, this spikes happens on all the channels, so I am > problay going to have to replace them all. If that can be done. >=20 > Regards.=20 The important aspect of the cable ground is not that it actually be a=20 good Earth connection, but that it be the potential that the high gain=20 amplifier considers to be the zero volt reference. If you tie the=20 cable shield to some actual Earth connection, you also need to tie the=20 amplifier zero volt reference to that same potential. This difficulty in doing this may be that it is already grounded at=20 some other point (say, through the computer power plug), so that=20 adding this second ground contact will produce what is called a ground=20 loop. The dual ground connection will try to equalize the=20 instantaneous potential at the two ground points by passing large=20 currents along the conductor that connects them. This current will=20 inject (by transformer coupling) noise into the signal lines that=20 parallel the line that connects the two grounds. This is why low noise systems are usually made with a very=20 specifically single point grounded system. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: spike problem From: ChrisAtUpw@....... Date: Sun, 4 Jun 2006 13:00:46 EDT In a message dated 04/06/2006, jonfr500@......... writes: I have connected the shield in the cable to the ground. Through a heating oven in the room, it uses hot water so it is ideal for this type of connection to the ground. That is going to eliminate the shield problem charging up, at least it I hope it does. The connection to the ground is fairly good. There is paint on the heating oven, but I don't think that is a problem. Now I only have to fix the larger spikes. Or replace the capacitor that is possible leaking, this spikes happens on all the channels, so I am probably going to have to replace them all. If that can be done. Hi John, Does your cold water supply or the hot water supply use copper / metal pipes? Look at the electric meter / fuse board/ trip board. There should be a thick green earth connection wire. Don't despair! Regards, Chris Chapman
In a message dated 04/06/2006, jonfr500@......... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>I have=20 connected the shield in the cable to the ground. Through a heating oven in= the=20 room, it uses hot water so it is ideal for this type of connection to the=20 ground. That is going to eliminate the shield problem charging up, at leas= t it=20 I hope it does. The connection to the ground is fairly good. There is pain= t on=20 the heating oven, but I don't think that is a problem.

Now I only h= ave=20 to fix the larger spikes. Or replace the capacitor that
is possible=20 leaking, this spikes happens on all the channels, so I am
probably goin= g to=20 have to replace them all. If that can be done.
Hi John,

Does your cold water supply or the hot water su= pply=20 use copper / metal pipes?
Look at the electric meter / fuse board/ trip=20 board. There should be a thick green earth connection wire.
Don't despair!

Regards,

Chris Chapman
Subject: Re: spike problem From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Sun, 04 Jun 2006 17:12:39 +0000 Hi It has two componment inside the cable, the shield has wires and it also is silver type skin over the actual cat-5 wires. > What length of cable in m are you using to connect the geophones to > the amplifier board? I use 15 meters. It is the minmal lenght I can use. > This difficulty in doing this may be that it is already grounded at > some other point (say, through the computer power plug), so that > adding this second ground contact will produce what is called a > ground > loop. I hope that doesn't happen. The shield is not connected to the amp board it self or to the geophone. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: spike problem From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Sun, 04 Jun 2006 17:16:57 +0000 Hi Chris. It's hot water. This is used to heat up my apartment. They use metal pipes, the whole system is ground connected at entry point inside the block. > Look at the electric meter / fuse board/ trip board. There should be a > thick green earth connection wire. I am unsure what you mean here. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: spike problem From: ChrisAtUpw@....... Date: Sun, 4 Jun 2006 13:28:30 EDT In a message dated 04/06/2006, jonfr500@......... writes: It's hot water. This is used to heat up my apartment. They use metal pipes, the whole system is ground connected at entry point inside the block. Hi Jon, Do you also have a metal pipe cold water supply? Or is it plastic? > Look at the electric meter / fuse board/ trip board. There should be a > thick green earth connection wire. I am unsure what you mean here. I presume that you pay for your electricity? There will be thick power cables entering your flat and there will be a main power fuse, a meter for recording how much electricity you use and a fuse box / board or circuit trip board with switches. Connected to this should be a thick earth wire, usually yellow and green or plain green. Regards, Chris Chapman
In a message dated 04/06/2006, jonfr500@......... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>It's hot=20 water. This is used to heat up my apartment. They use metal
pipes, the=20 whole system is ground connected at entry point inside=20 the
block.
Hi Jon,

Do you also have a metal pipe cold water supply= ? Or=20 is it plastic?
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>>=20 Look at the electric meter / fuse board/ trip board. There should be a
= >=20 thick green earth connection wire.

I am unsure what you mean=20 here.
I presume that you pay for your electricity? Th= ere=20 will be thick power cables entering your flat and there will be a main power= =20 fuse, a meter for recording how much electricity you use and a fuse=20 box / board or circuit trip board with switches. Connected to= =20 this should be a thick earth wire, usually yellow and green or plain=20 green.

Regards,

Chris Chapman
Subject: Re: spike problem From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Sun, 04 Jun 2006 17:36:52 +0000 Hi Chris Everything is connected to ground, it is by some regulation why that is done. I can't see the wire you descripe, it is hidden in the setup. The ground plug is in every electronic plug that is in my apartment. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: spike problem From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Sun, 04 Jun 2006 17:58:12 +0000 Hi The spikes continue. The only thing that has changed is that the smaller spikes appears to be gone. When the spike appars, the line appears to shift a little, not a alot, but a large enugh so that I can see it. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: spike problem From: John Popelish jpopelish@........ Date: Sun, 04 Jun 2006 14:13:43 -0400 J=F3n Fr=EDmann wrote: (snip) >>This difficulty in doing this may be that it is already grounded at=20 >>some other point (say, through the computer power plug), so that=20 >>adding this second ground contact will produce what is called a >>ground=20 >>loop. >=20 > I hope that doesn't happen. The shield is not connected to the amp boar= d > it self or to the geophone. But that means that the cable shield (that is intended to keep any=20 external electric fields from driving capacitive current signals into=20 any of the shielded conductors) is not necessarily grounded to a=20 potential that the amplifiers consider to be zero volts. The=20 instantaneous potential to one point on the Earth can be quite=20 different than the potential at some other point, since atmospheric,=20 subterranean and the electrical power system dump current into various=20 points on the Earth at any particular moment, and those currents drop=20 voltage as they spread out in the Earth. The only way a cable shield keeps external signals out of the shielded=20 conductors is if the shield is held at whatever potential the=20 receiving electronics considers to be zero volts. You need to find=20 the signal common (zero volts as far as the electronics sees the=20 universe) and tie the shield to that. If the geophone has a shield=20 connection, it also should be tied to that potential through the cable=20 shield, or a spare conductor running through that shield. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: spike problem From: ChrisAtUpw@....... Date: Sun, 4 Jun 2006 14:10:37 EDT In a message dated 04/06/2006, jonfr500@......... writes: Everything is connected to ground, it is by some regulation why that is done. I can't see the wire you descripe, it is hidden in the setup. The ground plug is in every electronic plug that is in my apartment. Hi Jon, That it usual. Do you have power fuses that can be replaced, or do you have a row of switches for the various circuits? Is your cold water supply in metal of plastic pipes? Look under the handbasin in the bathroom? It has two componment inside the cable, the shield has wires and it also is silver type skin over the actual cat-5 wires. Make a connection from the shield wires in the cabler to the 0 V rail on your amplifier board. It does not matter which of the three. This should greatly reduce the spike problems. I did suggest that you use six core cable with a plaited copper screen. This cable has six plastic insulated colour coded wires, a plaited bare copper screen and a PVC sheath. Could you not buy any? It is likely to be much better that cat5 cable. Regards, Chris Chapman
In a message dated 04/06/2006, jonfr500@......... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000=20 size=3D2>Everything is connected to ground, it is by some regulation why t= hat=20 is
done. I can't see the wire you descripe, it is hidden in the setup.=20 The
ground plug is in every electronic plug that is in my=20 apartment.
Hi Jon,

That it usual. Do you have power fuses that can= be=20 replaced, or do you have a row of switches for the various circuits?

Is your cold water supply in metal of plastic=20 pipes? Look under the handbasin in the bathroom?

<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>It has=20 two componment inside the cable, the shield has wires and it also
is si= lver=20 type skin over the actual cat-5 wires.
Make a connection from the shield wires in the=20 cabler to the 0 V rail on your amplifier board. It does not matter which of=20= the=20 three.
This should greatly reduce the spike problems.=20

I did suggest that you use six core cable with=20= a=20 plaited copper screen. This cable has six plastic insulated colour code= d=20 wires, a plaited bare copper screen and a PVC sheath. Could you not buy any?= It=20 is likely to be much better that cat5 cable.

Regards,

Chris Chapman
Subject: Re: spike problem From: Larry Cochrane lcochrane@.............. Date: Sun, 04 Jun 2006 12:46:10 -0700 Hi Jón, The electronic parts inside the sensor are resistors used for damping. They are not capacitors. The resistors should not be removed. Regards, Larry Cochrane Redwood City, PSN Jón Frímann wrote: > Hi > >> Did you connect up the shield (screen) of the cable to the ground of the Amp/Filter >> board? > > The two colored wire is connected to the amp board properly, the same > goes for the single colored one. This happens also with a cat-5 cable > that is not screened, I was using that before I got screened cable. The > sheld it self is not connected to anything, since I can't connect it to > the ground, at least I don't know how to connect it to the ground. Since > I don't see any connection for it. I know that the problem is not in the > amp board. There are capacitors inside the geophone, I think that thease > are capacitors. I can ground the shield of the cat-5 cable. If I get > some instructions on how to do it. I can also replace the capacitors if > I know what to buy and how to replace them. I know about good electronic > store in Iceland that sells this type of items. > > This spike problem has been getting worse since I got the geophone, it > was not there in the early start. In the past 2 months it has been > getting really bad. > > Regards. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: spike problem From: ChrisAtUpw@....... Date: Sun, 4 Jun 2006 18:43:56 EDT In a message dated 04/06/2006, jonfr500@......... writes: Yes, I have cordless telephone. But thease spikes happen even if the phone is not ringing at all. Hi Jon, Is the main phone distribution aerial any where near you? Thie could be calling a lot of other pnones in the area. Regards, Chris Chapman
In a message dated 04/06/2006, jonfr500@......... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>Yes, I=20 have cordless telephone. But thease spikes happen even if the
phone is=20= not=20 ringing at all.
Hi Jon,

Is the main phone distribution aerial any w= here=20 near you? Thie could be calling a lot of other pnones in the area.

Regards,

Chris Chapman

In a message dated 06/06/2006, jonfr500@......... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>>=20 Have you connected the shield wire to the ground connection on the board=20 yet?

No. I don't know where it is on the board. I've been trying to= =20 look for
Hi Jon,

Do you have the http://psn.quake.net/serialamp.= html
or the http://psn.quake.net/eqamp.html=  amplifier=20 board?
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>I am=20 going to have to buy a 330 ohm resistor. I know that if I
disconnect= the=20 geophone cable from the amplifer board. I get flat line
and no spikes a= t=20 all.
Great news! Then you don't need to buy any 330=20= ohm=20 resistors! You are seeing pickup on the cable.
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>>=20 (All of your connections are soldered aren't they? If not, then do=20 so.)

Connection inside the geophone are soldered properly. I have=20 terminal
block screws on the amplifer board.
? Neither of Larry's boards usually have screw=20 connectors? The boards usually have phono connectors. The outside ring with=20= two=20 solder connections is the 0V line.

Look at the back of the amplifier board ne= ar=20 the inputs.  One input will have a short narrow track leading to pin 3=20= of=20 the opamp and a 10 K Ohm resistor. The other twin 0V inputs will have a wide= =20 track across the board.

Do you have an electric / electronic measuring=20 meter?

Regards,

Chris Chapman
Hi All,

For the lack of worksop and tools, and also due to what someone else recently called 'brain-fade' :) I have given up on building a Lehman Sensor on my own. I will really appreciate if someone has parts available for sale that I can assemble to make a Lehman sensor. I can take care of the electronics and magnets and other stuff myself. Feel free to contact me at jatinip@yahoo.com.

Thanks!

Jatin
==========

In a message dated 08/06/2006, gpayton880@....... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>Entering=20 a new "hobby" or interest, one always has a ton of questions.  But,=20
to avoid ruining my welcome too fast, I will list just a few general=20
questions.
Hi Gerald,

I suggest that you download and read http://psn.quake.net/info/an= alysis.pdf =20 It describes the main characteristics of earthquakes.
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>1) =20   Geophone vs. Seismometer?
2)    Vertical or=20 Horizontal?
3)    Resonant Frequency? 1, 4.5, 8, or=20 10Hz.?
Working back up the list, 8 or 10 Hz geophones=20= are=20 all but useless for detecting earthquakes, unless you live on a live volcano= ..=20 When a frequency of say 10 Hz is quoted, this is the natural resonant freque= ncy.=20 They are normally critically damped and the upper limit may be over 20x this= and=20 quite flat to velocity.

Earthquakes generate fast compressional P waves= (1=20 to 0.5 sec and less), slower lateral S waves (2 to 1 sec and less) and when=20 these interact with the earth's surface, long period lateral Love waves and=20 vertical Rayleigh waves are generated (10 to >40 sec).
Notice that you do need to consider the=20 polarisation as well as the period. The higher frequencies generated at the=20 quake source are selectively absorbed as they travel through the earth.

It is usual to limit amateur systems with a low= =20 pass filter set at 10 or 20 Hz. This greatly reduces the ambient cultural no= ise,=20 which may be severe at over 20 Hz.

While 4.5 Hz geophones can be used 'as supplied= '=20 for local quakes, they are of quite limited use for regional quakes and may=20= only=20 sense very large teleseismic quakes. They are, however, reasonably inexpensi= ve.=20 New ones may cost \$60 each. Larry has some secondhand three axis=20 ones in waterproof plastic containers, from \$58.
The response can be extended down to 0.5 Hz (2=20= sec)=20 using a compensating amplifier. These do add some noise, but they are reason= ably=20 good and do then enable you to pick up both regional and teleseismic P and S= =20 waves.

1 Hz geophones are generally OK and are used in= =20 geophysical fieldwork, but they are much more expensive. New ones cost about= =20 \$1,500.
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>I have=20 spent hours today reading various articles and from different
websites= =20 until my eyes crossed and I had Brain Fade.  Some of the material=20
"may" be outdated too. That is one of my "gripes" about the=20
internet.......no way to determine the age of a posted=20 document.
One source of dated information is psn letters.= You=20 can download 4 parts per year, expand them and put them into an annual=20 file. This can then be searched using your word processor.
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>As I=20 understand it, for long distance reception, you need a more sensitive=20
seismometer rather than a geophone. However, I could see where a=20 sensitive
one might be overwhelmed with a nearby quake. I live in= a=20 rural area in NW
Arkansas and the closest activity probably would be t= he=20 New Madrid fault
area.
You can buy boards with one to three 'stro= ng=20 motion' sensors on them, but they tend to be fairly expensive. They are like= ly=20 to be limited by internal noise.
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>I doubt=20 that I want to build anything unless it is a kit form. Is there an=20
soundboard interface software or hardware nowadays. Where are the=20
economical commercial, kits and ready-built systems=20 available?
The 1 and 4.5 Hz geophones will give you signal= s=20 limited primarily by your ambient local noise. For longer period signals, yo= u=20 need to use Lehman or SG seismometers.

There are no US kits as far as I know. This is=20= very=20 much a DIY hobby. You can buy the electronic amplifiers, ADCs and GPS time=20 receivers. You can buy a simple 'demonstration' vertical as used in some=20 schools, see http://jclahr.com/scie= nce/psn/as1/index.html

The nearest thing to a kit is the complete=20 electronics for a SG seismometer sold by Larry. You just have to make a pend= ulum=20 of about 1 sec period. This will give you sensitivity to horizontal motion f= lat=20 from about 20 sec to 10 Hz
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>Amateur=20 Radio is full of different interfaces and uses for a=20 soundboard.
Work it out! You are considering recording mayb= e=20 three data channels over periods of years. Even at their lowest rate,=20 soundboards would generate hopelessly large data files.
You need maybe 20 samples / sec at 16 bits=20 resolution per channel. You also have to scan for and analyse the seism= ic=20 signals. This requires specialist software.
You need a clock timing system which is accurat= e to=20 better than 0.5 sec at all times. The software clocks on PCs may show=20 errors of 30 sec per day. The 'sort-of' clock which behaves= =20 least like a clock! An alternative is to use an accurate on-li= ne=20 time service like 'AboutTime' from  http://www.arachnoid.com/aboutt= ime/ =20 Only a few on-line services check for propagation delays, which can be up to= =20 several seconds due to digital queueing on the internet, if you are=20 unlucky. You may also search for a 'local' time server which has an analogue= =20 phone connection.

Hope that this helps!

`   Chris Chapman

Does anyone have any GOOD photos of a completed Lehmann = Sensor?  So far, all I have found are text instructions poorly = written and=20 crudely drawn sketches.  It sure would be helpful for me as a=20 newbie.

It is OK for your sending them directly to me at gpayton880@....... or ab5r@........ .

So far, I have only received one reply to my "Newbie Questions" = previously=20 sent.  (Thank you, Chris.)  It was very helpful, but a lot of=20 questions still are bouncing around in my head.  I'll eventually = get around=20 to asking them later, as I learn more and can hopefully propose an = intelligent=20 question.

Gerald Payton
Subject: Re: Lehmann Sensor Diagram From: ChrisAtUpw@....... Date: Fri, 9 Jun 2006 12:37:43 EDT In a message dated 09/06/2006, gpayton880@....... writes: Does anyone have any GOOD photos of a completed Lehmann Sensor? I have a scale drawing if that would be any use? I use two 1/4" thick bright mild steel plates, 2" wide by 3.5" long. They are held apart by 3 or 4 zinc plated 3" mild steel set screws with three nuts each. On the centre inside of both plates I fit two 1" square by 1/8" thick NdFeB square magnets to give an arrangement -> Bolt Bolt XXXXXXXXXXXXXXXXXXXXXXX Backing plate NNNNSSSS <-- Coil --> SSSSNNNN XXXXXXXXXXXXXXXXXXXXXXX Backing plate Bolt Bolt I find that this works very well and it is easy to adjust. The coil that I use came as a spare for a 220V water valve on a washing machine and it is about 3/8" thick by slightly over 1" OD, about 5,000 turns. I use the same layout but with 1"x1/2"x1/4" NdFeB magnets for the 1/16" Cu damping plate. Any internal field inbalance is shorted through the bolts and the external field is near zero. Hope that this helps. Regards, Chris Chapman
In a message dated 09/06/2006, gpayton880@....... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>Does=20 anyone have any GOOD photos of a completed Lehmann=20 Sensor?
I have a scale drawing if that would be any=20 use?

I use two 1/4" thick bright mild steel pla= tes,=20 2" wide by 3.5" long. They are held apart by 3 or 4 zinc plated 3" mild stee= l=20 set screws with three nuts each. On the centre inside of both plates I fit t= wo=20 1" square by 1/8" thick NdFeB square magnets to give an arrangement ->

Bolt           &= nbsp;            = ;    Bolt
XXXXXXXXXXXXXXXXXXXXXXX Backing plate
NNNNS= SSS
= ;<--=20 Coil -->
SSSSN= NNN
XXXXXXXXXXXXXXXXXXXXXXX Backing plate
Bolt           &= nbsp;            = ;    Bolt

I find that this works very well and it is easy= to=20 adjust. The coil that I use came as a spare for a 220V water valve on a wash= ing=20 machine and it is about 3/8" thick by slightly over 1" OD, about 5,000=20 turns.
I use the same layout but with 1"x1/2"x1/4" NdF= eB=20 magnets for the 1/16" Cu damping plate.
Any internal field inbalance is shorted through= the=20 bolts and the external field is near zero.

Hope that this helps.

Regards,

Chris Chapman
PSN friends--perhaps you have noticed the Rat = Island swarm=20 of seismic events---over 50 in the first 12 hours UT of June 14, = '06. =20 Magnitudes range from 2.5 to 6.3.
For those in range of 2 or more of = these=20 events--such conditions make for good magnitude comparisons & local = system=20 calibration.
Latitude and longitude & depths = of=20 origins vary a bit.  One can stand amazed at the resolution the=20 professionals have in a swarm as this.
A good day to all----Jim=20 Lehman
Subject: RE: Google Earth From: "Charles Spedener" charelsp@..... Date: Wed, 14 Jun 2006 20:34:51 +0200 Hi all,=20 Another interesting program to monitor quakes, volcanoes etc is = earthbrowser (www.earthbroser.com, a smart small peace of software. Charles -----Original Message----- From: psn-l-request@.............. [mailto:psn-l-request@............... = On Behalf Of J=F3n Fr=EDmann Sent: Mittwoch, 14. Juni 2006 01:19 To: PSN-Postlist Subject: Google Earth Hi all I just found out that google earth is good to locate volcanos and to get info on where large earthquakes have happen in the past. For those who haven't tested google earth, I recommend that they do. Since it is handy for those of us recording earthquakes and monitoring volcanos. Regards. --=20 J=F3n Fr=EDmann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) ____________ Virus checked by G DATA AntiVirusKit Version: AVK 16.7886 from 14.06.2006 Virus news: www.antiviruslab.com __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: Google Earth From: "Timothy Carpenter" geodynamics@....... Date: Wed, 14 Jun 2006 15:43:31 -0400 Charles, you forgot the "W" in earthbroser it should be:=20 www.earthbrowser.com, not >www.earthbroser.com< -Tim- Timothy Carpenter,=20 5043 Whitlow Court Commerce Township, Michigan 48382 -----Original Message----- From: psn-l-request@.............. [mailto:psn-l-request@............... = On Behalf Of Charles Spedener Sent: Wednesday, June 14, 2006 2:35 PM To: psn-l@.............. Subject: RE: Google Earth Hi all,=20 Another interesting program to monitor quakes, volcanoes etc is = earthbrowser (www.earthbroser.com, a smart small peace of software. Charles -----Original Message----- From: psn-l-request@.............. [mailto:psn-l-request@............... = On Behalf Of J=F3n Fr=EDmann Sent: Mittwoch, 14. Juni 2006 01:19 To: PSN-Postlist Subject: Google Earth Hi all I just found out that google earth is good to locate volcanos and to get info on where large earthquakes have happen in the past. For those who haven't tested google earth, I recommend that they do. Since it is handy for those of us recording earthquakes and monitoring volcanos. Regards. --=20 J=F3n Fr=EDmann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) ____________ Virus checked by G DATA AntiVirusKit Version: AVK 16.7886 from 14.06.2006 Virus news: www.antiviruslab.com __________________________________________________________ Public Seismic Network Mailing List (PSN-L) __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Rat Island Swarm From: Barry Lotz barry_lotz@............. Date: Wed, 14 Jun 2006 20:10:16 -0700 (PDT) Hi Jim What I find interesting is that USGS shows two 6+ events about 30 minutes apart. I have a hard time seeing the second event start (P & S wave arrivals). It's like my sensors focus on the first event. I don't have a problem with local events though. Regards barry Connie and Jim Lehman wrote: PSN friends--perhaps you have noticed the Rat Island swarm of seismic events---over 50 in the first 12 hours UT of June 14, '06. Magnitudes range from 2.5 to 6.3. For those in range of 2 or more of these events--such conditions make for good magnitude comparisons & local system calibration. Latitude and longitude & depths of origins vary a bit. One can stand amazed at the resolution the professionals have in a swarm as this. A good day to all----Jim Lehman
Hi Jim
What I find interesting is that USGS shows two 6+ events about 30 minutes apart. I have a hard time seeing the second event start (P & S wave arrivals). It's like my sensors focus on the first event. I don't have a problem with local events though.
Regards
barry

Connie and Jim Lehman <lehmancj@...........> wrote:
PSN friends--perhaps you have noticed the Rat Island swarm of seismic events---over 50 in the first 12 hours UT of June 14, '06.  Magnitudes range from 2.5 to 6.3.
For those in range of 2 or more of these events--such conditions make for good magnitude comparisons & local system calibration.
Latitude and longitude & depths of origins vary a bit.  One can stand amazed at the resolution the professionals have in a swarm as this.
A good day to all----Jim Lehman

Subject: Norway meteor... From: "Kareem from Heyjoojoo.Com" system98765@............. Date: Wed, 14 Jun 2006 22:36:12 -0700 What's the latest with the meteorite landing in Norway? Did anyone find any of it? Kareem Lanier www.heyjoojoo.com www.myspace.com/heyjoojoo 37.97 N, 122.30 W __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Norway meteor... From: "Geoffrey" gmvoeth@........... Date: Thu, 15 Jun 2006 06:27:23 -0700 People must get hurt or America is not interested in reporting it. I think we are the bloodiest society on Earth. ----- Original Message ----- From: "Kareem from Heyjoojoo.Com" To: "PSN" Sent: Wednesday, June 14, 2006 10:36 PM Subject: Norway meteor... > What's the latest with the meteorite landing in Norway? Did anyone find any > of it? > > > > > Kareem Lanier > www.heyjoojoo.com > www.myspace.com/heyjoojoo > 37.97 N, 122.30 W > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Norway meteor... From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Thu, 15 Jun 2006 13:35:53 +0000 Hi They now belive it shattered on it's way down to the surface of the planet. There is still a search for fragments from the metior, and they offer up to 1 million nrkr (norsk krona) (I think) for thease fragments as a price for them. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Norway meteor... From: "Jerry Payton" gpayton880@....... Date: Thu, 15 Jun 2006 08:39:10 -0500 You just PROVED my point. "Never argue with an idiot, they'll drag you down to their level and beat you with experience" - anon
You just PROVED my point.

"Never argue with an idiot, they'll drag you down to their level = and beat=20 you with experience" - anon
In a message dated 15/06/2006, gmvoeth@........... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>I only=20 wanted to let people know there has been no news on Arizona TV or RADIO ab= out=20 the Norway Meteor as far as I can tell.
It also does not report other=20 things except silly Human Interest stuff
As for real time intelligence=20= we=20 live in a kind of black hole of ignorance.
Hi Geoff,

Following on http://w= ww.aftenposten.no/english/local/article1346411.ece=20
There is now an update at http://w= ww.aftenposten.no/english/local/article1353224.ece
It seems the meteor wasn't quite a large as fir= st=20 reported, but it was picked up on the seismic and infrasound detectors.= =20
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>I really=20 miss decent real time intelligence we used to get in military
The only=20 reason I subscribe to PSN is because it gives me some of this real time=20 intelligence the regular news lacks.
You may need to tease out a few facts= =20 from propaganda and 'spin' in your news media, even on scientific=20 matters. Some still seem to be questioning climate change.
Reuters and the BBC seem fairly reliable.

Regards,

Chris Chapman
Subject: Diffrence between a tectonic earthquake and a volcano type of From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Fri, 16 Jun 2006 00:29:43 +0000 Hi all What is the main diffrance between a tectonic type of earthquake and a volcano type of earthquake. Earlyer this evening i did recorod a earthquake that had his main energy around 5Hz at least. It didn't show well on higer hz, but was recorded farly good at my station at lower frequancyes. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Eh em... From: "Kareem from Heyjoojoo.Com" system98765@............. Date: Thu, 15 Jun 2006 18:15:31 -0700 Ok. So, where were we again? Meteorite fragments have yet to be found? By the way, the San Francisco Bay Area was jolted this morning (05:25 am PDT) by a M4.7 quake. It's been a couple of years since we've had one of that size in this area. Noticed yesterday evening that our weather seemed a bit "kooky" perhaps "earthquake weather-ish" whatever that means. How's that for starting a new intellectual topic. Hope you all see it that way. Kareem Kareem Lanier www.heyjoojoo.com www.myspace.com/heyjoojoo 37.97 N, 122.30 W __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: Norway meteor... From: "Timothy Carpenter" geodynamics@....... Date: Thu, 15 Jun 2006 21:38:03 -0400 According to the referenced document, dated June 9, it appears DIVINE = STRAKE has been indefinitely postponed. Apparently the original "Finding of No Significant Impact" couldn't stand up to the intense scrutiny. There's = no indication of when the test might be rescheduled - but it doesn't look = like they'll meet the June 23 date.=20 =20 =20 http://www.nv.doe.gov/library/publications/Environmental/WithdrawalRevise= dFi nding.pdf =20 -Tim- =20 Timothy Carpenter Commerce Twp., Michigan

According to the referenced document, dated June 9, it appears DIVINE STRAKE has been = indefinitely postponed. Apparently the original “Finding of No Significant = Impact” couldn’t stand up to the intense scrutiny. There’s no = indication of when the test might be rescheduled – but it doesn’t look = like they’ll meet the June 23 date.

http://www.nv.doe.gov/library/public= ations/Environmental/WithdrawalRevisedFinding.pdf

-Tim-

Timothy Carpenter

Commerce Twp., Michigan

Subject: Re: Norway meteor... From: ChrisAtUpw@....... Date: Fri, 16 Jun 2006 01:33:53 EDT =20 In a message dated 16/06/2006 02:38:54 GMT Daylight Time, =20 geodynamics@....... writes: According to the referenced document, dated June 9, it appears DIVINE STRAK= E=20 has been indefinitely postponed. Apparently the original =E2=80=9CFinding o= f No=20 Significant Impact=E2=80=9D couldn=E2=80=99t stand up to the intense scruti= ny. There=E2=80=99s no=20 indication of when the test might be rescheduled =E2=80=93 but it doesn=E2= =80=99t look like they=E2=80=99 ll meet the June 23 date. =20 _http://www.nv.doe.gov/library/publications/Environmental/WithdrawalRevisedF= in ding.pdf_=20 (http://www.nv.doe.gov/library/publications/Environmental/WithdrawalRevisedF= inding.pdf)=20 Hi Tim, =20 Given that this was to be an underground HE ammonium nitrate test bast,= =20 the excuses for cancellation seem to be false. =20 Regards, =20 Chris Chapman
In a message dated 16/06/2006 02:38:54 GMT Daylight Time,=20 geodynamics@....... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000080 size= =3D2>

According to th= e=20 referenced document, dated June 9, it appears DIVINE STRAKE has been=20 indefinitely postponed. Apparently the original =E2=80=9CFinding of No Sig= nificant=20 Impact=E2=80=9D couldn=E2=80=99t stand up to the intense scrutiny. There= =E2=80=99s no indication of=20 when the test might be rescheduled =E2=80=93 but it doesn=E2=80=99t look l= ike they=E2=80=99ll meet the=20 June 23 date.

http://www.nv.doe.gov/library/publications/Environmenta= l/WithdrawalRevisedFinding.pdf

Hi Tim,

Given that this was to be an underground HE=20 ammonium nitrate test bast, the excuses for cancellation seem to b= e=20 false.

Regards,

Chris Chapman

I don't know about other types of vault but I would say, having glimpsed at the diagram: =A0If you are going to this much effort, make it big enou= gh for future additions, ie space to add a Lehman or 2. =A0Also, access to a= djust things doesn't look easy from the diagram. =A0I would also angle the cabl= e entry tube down the way to discourage water coming in.

Cheers

Ian

J=F3n Fr=EDmann wrote:
Hi

I plan to move my geophone out, but I need to do it properly. So it
doesn't get flooded with water and get's damaged becose of that.

I want to build this type of seismic vault,
http://www.iris.iris.edu/passcal/Manual/rtfm.=
sa11.2.html (see pdf file
for picture). There is alot of water becose of a snow during the winter
that I need to protect my geophone from. If there are any other types of
seismic vaults that I might consider, please let me know. I am still on
the planning stage, but I plan to build this next month, if I can.

Regards.

--

Subject: Re: seismic vault From: "Jerry Payton" gpayton880@....... Date: Tue, 20 Jun 2006 10:01:57 -0500 Is Environmental Stability (temperature & humidity) within the vault an issue? You might consider that too. The points given by Ian's reply are valid too. Good luck. Gerald Payton ----- Original Message ----- From: Jón Frímann To: PSN-Postlist Sent: Tuesday, June 20, 2006 9:26 AM Subject: seismic vault Hi I plan to move my geophone out, but I need to do it properly. So it doesn't get flooded with water and get's damaged becose of that. I want to build this type of seismic vault, http://www.iris.iris.edu/passcal/Manual/rtfm.sa11.2.html (see pdf file for picture). There is alot of water becose of a snow during the winter that I need to protect my geophone from. If there are any other types of seismic vaults that I might consider, please let me know. I am still on the planning stage, but I plan to build this next month, if I can. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email PSN-L-REQUEST@.............. with the body of the message (first line only): unsubscribe See http://www.seismicnet.com/maillist.html for more information.
Is Environmental Stability (temperature & = humidity) within the vault an issue?  You might consider that too. = The=20 points given by Ian's reply are valid too.  Good luck.

Gerald Payton

----- Original Message -----
From:=20 J=F3n = Fr=EDmann=20
Sent: Tuesday, June 20, 2006 = 9:26=20 AM
Subject: seismic vault

Hi

I plan to move my geophone out, but I need to = do it=20 properly. So it
doesn't get flooded with water and get's damaged = becose of=20 that.

I want to build this type of seismic vault,
http://= www.iris.iris.edu/passcal/Manual/rtfm.sa11.2.html=20 (see pdf file
for picture). There is alot of water becose of a snow = during=20 the winter
that I need to protect my geophone from. If there are = any other=20 types of
seismic vaults that I might consider, please let me know. = I am=20 still on
the planning stage, but I plan to build this next month, = if I=20 can.

Regards.
--
J=F3n Fr=EDmann
http://www.jonfr.com
http://www.simnet.is/j= onfr500/earthquake/

__________________________________________= ________________

Public=20 Seismic Network Mailing List (PSN-L)

To leave this list email = PSN-L-REQUEST@............... =20 with
the body of the message (first line only): unsubscribe
Steve Hammond in Aptos has a couple he'd like to give away... and I have a couple in Gilroy I'd even deliver to a reasonable distance... just to see that they get a good home.

Jan Froom

Erich Kern wrote:
All,

Not only is the shipping expensive, I am not willing to spend the time and money to pack it
properly and transport it to a freight office. That is why I said "pickup only".  It should be
bolted to the inside of a plywood box for shipping so it doesn't shift around. Whomever agrees
to come to Murrieta, Calif. to pick it up will be the one who takes it away.

If nobody wants it in a month it will go to a scrap metal dealer.

Cheers,
Erich

----- Original Message -----
From: "Jón Frímann" <jonfr500@.........>
To: <psn-l@..............>
Sent: Tuesday, June 20, 2006 5:56 PM
Subject: Re: Free Drum Recorder Available

Hi

I have intrest, but I am like in Iceland and stuff like that is heavy in
transport with the mail, there it is going to cost more in shipping. I
am shorta short on shipping money for the moment. Willing to get this,
but unable. :-(

Unless you can hold it for the next 9 to 14 days. Then I can take a good
look at this and see if I can afford a shipping to Iceland.

Regards.

In a message dated 20/06/2006 15:26:09 GMT Daylight Time,=20 jonfr500@......... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>I plan=20 to move my geophone out, but I need to do it properly. So it
doesn't ge= t=20 flooded with water and gets damaged because of that.

I want to buil= d=20 this type of seismic=20 vault,
http://www.iris.iris.edu/passcal/Manual/rtfm.sa11.2.html (see pd= f=20 file
for picture). There is a lot of water because of a snow during the= =20 winter
that I need to protect my geophone from. If there are any other=20 types of
seismic vaults that I might consider, please let me=20 know.
Hi Jon,

This particular vault is NOT WATERPROOF and you= can=20 expect it to flood when the snow melts and during heavy rain. Sorry, bu= t I=20 am near certain that it will NOT be satisfactory for your location in=20 Iceland. The geophone case will float if the water level rises.

Your geophones are enclosed in a waterproof pla= stic=20 case. It is quite easy to seal both the case and the cable glands with silic= one=20 rubber paste. You need to buy the sort of silicone rubber which does NOT sme= ll=20 strongly of acetic / formic acid. You could then wrap the case in thin plast= ic=20 foam sheet and put the whole lot inside polythene bags tied around= the=20 cable, to protect it from freezing. You could align the sensor and bury it i= n=20 sand at the bottom of a hole. You might need to put a weight / bricks / rock= s on=20 top of the case to prevent it moving if submerged.

Another alternative might be to use a plastic d= rain=20 manifold. These are vertical plastic tubes with blanked off connections= for=20 horizontal drain pipes. Some of them can be completely sealed - check before= you=20 buy one. At least two sizes are available, but they are not cheap.
You could fit a tank connector and plastic= =20 water pipe onto one of the blanking plates to house the geophone=20 cable. You could partially fill the main case with dry sand and mount the=20 geophone case on top on a glass or glazed ceramic disk.
Fit a plastic reducing connector to the end of=20= the=20 water pipe and seal the tube to the cable with black 'Self Amalgamating Tape= '.=20 You stretch the tape to tension and thin it and wrap overlapping turns=20= over=20 the joint. This provides an airtight and UV / solar resistant seal. You= =20 should also seal the end of the multiway cable with silicone rubber paste. T= his=20 prevents air pressure changes carrying damp air into the cable and prevents=20 corrosion

There are a number of installations described o= n=20 the Guralp website
See http://www.guralp.net/gene= ral/customers/ and=20 for a waterlogged site
http://www.guralp.net/articles/20040400-casestudy-eskdalemuir/support=

<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>> Is=20 Environmental Stability (temperature & humidity) within the vault an=20 issue?

I don't think it is going to be a problem inside the vault.=20 Since I need
to place it at least 2 meters below the surface (if I can=20= even=20 get that
deep), because of the winter frost where I live.
I doubt if you will need to go to a depth of 2=20 m, but it is possible. I would have expected 1 m to be adequate. Do you= =20 have any idea of the freezing level in your soil? Can you look up the minimu= m=20 soil temperatures that you can expect at various depths? The Icelandic=20 Meteorological Service should have daily soil temperatures at several depths= , if=20 not at more frequent intervals. You might send an EMail to halldor@........? The company which sup= plies=20 your drinking water should also have figures - they need to keep the supplie= s=20 free of ice in winter.

Regatds,

Chris Chapman

Subject: Re: seismic vault From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Wed, 21 Jun 2006 21:14:50 +0000 Hi Chris My other option, that I know about is this type of vault. http://www.indiana.edu/~pepp/manuals/vault.html The problem is the amount of spring melt I get and the winter melt I get also. There are also summer rain. The state supplyes the water here, I know a guy who works there and he told me that they go down to 70 - 80 cm down. I am going to have to have a drain, since the alterntive means that the vault is going to flood in the next rain I get. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: seismic vault From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Wed, 21 Jun 2006 23:10:21 +0000 Hi I forgot, the land where I plan my seismic vault isn't flat, it has some slope to it (right word? I don't know..). I am going to place it on a solid rock that is close to my apartment, becose of that, there is small hill, since the rock is a bit higer then the ground around it. It has enugh soil for me to place it at least 70 cm below ground. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: seismic vault From: John Popelish jpopelish@........ Date: Wed, 21 Jun 2006 19:57:50 -0400 J=F3n Fr=EDmann wrote: > Hi >=20 > I forgot, the land where I plan my seismic vault isn't flat, it has som= e > slope to it (right word? I don't know..). I am going to place it on a > solid rock that is close to my apartment, becose of that, there is smal= l > hill, since the rock is a bit higer then the ground around it. It has > enugh soil for me to place it at least 70 cm below ground. If you cover this vault with a concrete lid that hangs down a bit=20 below the top edges of the walls, and provide a drain path around the=20 vault for surface drainage, I think this would work pretty well. I=20 don't think you should try to bury that cover but keep it above the=20 surface to keep water out), but you might isolate it a bit from wind=20 and temperature changes by placing an insulated pyramidal plywood roof=20 over it. You will still need a down slope drain at the bottom of the=20 vault. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Large earthquake soon to happen in the southern part San Andreas From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr500@......... Date: Thu, 22 Jun 2006 00:09:53 +0000 Hi I am reading in Icelandic news that a experts are exspecting a large earthquake on the southern part of the San Andreas fault line. Here is a news about this in english, http://news.nationalgeographic.com/news/2006/06/060621-earthquakes.html With a 200 years build up of stress, this one might be big one, at least 8.5+ magnitue. This appears to be just a question of time when the quake happens. Regards. -- Jón Frímann http://www.jonfr.com http://www.simnet.is/jonfr500/earthquake/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Help! California From: Ian Smith ian@........... Date: Thu, 22 Jun 2006 07:29:59 +0100 Hi, I wonder if there is someone in the group who could help me with a shipping from California pickle I've gotten into. My DAQ system broke down last week and I've bought a National Instruments daq board from ebay: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=7627538876&ru=http%3A%2F%2Fsearch.ebay.com%3A80%2Fsearch%2Fsearch.dll%3Ffrom%3DR40%26satitle%3D7627538876%26fvi%3D1 The seller is insisting on using their own packing box instead of a standard Fedex box and this is pushing up the shipping costs to \$173! If they were to use a Fedex box it would only be \$68. So, I was wondering if anybody lived close to the seller (Folger Ave.Berkeley, CA 94710 - if you are within walking distance, they have a pickup service), if I could have it shipped to you for onward shipping (USPS or something) and I would reimburse the costs. Any help would be appreciated. I've just sent one last email to the seller asking them to use a Fedex box but I'm not optimistic that I'll succeed. TIA Ian Smith Hi,

I wonder if there is someone in the group who could help me with a shipping from California pickle I've gotten into.  My DAQ system broke down last week and I've bought a National Instruments daq board from ebay: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=7627538876&ru=http://search.ebay.com:80/search/search.dll%3Ffrom%3DR40%26satitle%3D7627538876%26fvi%3D1

The seller is insisting on using their own packing box instead of a standard Fedex box and this is pushing up the shipping costs to \$173!  If they were to use a Fedex box it would only be \$68.  So, I was wondering if anybody lived close to the seller (Folger Ave.Berkeley, CA 94710 - if you are within walking distance, they have a pickup service), if I could have it shipped to you for onward shipping (USPS or something) and I would reimburse the costs.

Any help would be appreciated.  I've just sent one last email to the seller asking them to use a Fedex box but I'm not optimistic that I'll succeed.

TIA

Ian Smith

Subject: Re: Help! California From: Larry Cochrane lcochrane@.............. Date: Wed, 21 Jun 2006 23:39:38 -0700 Hi Ian, I'm not within walking distance but you can have them send the package to me and I will resend it to you using USPS. My address is on this page http://www.seismicnet.com/contact.html. Regards, Larry Cochrane Redwood City, PSN Ian Smith wrote: > Hi, > > I wonder if there is someone in the group who could help me with a > shipping from California pickle I've gotten into. My DAQ system broke > down last week and I've bought a National Instruments daq board from > ebay: > http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=7627538876&ru=http://search.ebay.com:80/search/search.dll%3Ffrom%3DR40%26satitle%3D7627538876%26fvi%3D1 > > The seller is insisting on using their own packing box instead of a > standard Fedex box and this is pushing up the shipping costs to \$173! > If they were to use a Fedex box it would only be \$68. So, I was > wondering if anybody lived close to the seller (Folger Ave.Berkeley, CA > 94710 - if you are within walking distance, they have a pickup service), > if I could have it shipped to you for onward shipping (USPS or > something) and I would reimburse the costs. > > Any help would be appreciated. I've just sent one last email to the > seller asking them to use a Fedex box but I'm not optimistic that I'll > succeed. > > TIA > > Ian Smith > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Your message to the psn-l mailing list From: Ian Smith ian@........... Date: Thu, 22 Jun 2006 08:25:18 +0100 Hi, Thanks Larry, much appreciated. I'll get back to you offline... Cheers Ian postmaster@.............. wrote: >The attached message has been sent to the psn-l mail list. > > > > ------------------------------------------------------------------------ > > Subject: > Help! California > From: > Ian Smith > Date: > Thu, 22 Jun 2006 07:29:59 +0100 > To: > psn-l@.............. > > > Hi, > > I wonder if there is someone in the group who could help me with a > shipping from California pickle I've gotten into. My DAQ system broke > down last week and I've bought a National Instruments daq board from > ebay: > http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=7627538876&ru=http://search.ebay.com:80/search/search.dll%3Ffrom%3DR40%26satitle%3D7627538876%26fvi%3D1 > > The seller is insisting on using their own packing box instead of a > standard Fedex box and this is pushing up the shipping costs to \$173! > If they were to use a Fedex box it would only be \$68. So, I was > wondering if anybody lived close to the seller (Folger Ave.Berkeley, > CA 94710 - if you are within walking distance, they have a pickup > service), if I could have it shipped to you for onward shipping (USPS > or something) and I would reimburse the costs. > > Any help would be appreciated. I've just sent one last email to the > seller asking them to use a Fedex box but I'm not optimistic that I'll > succeed. > > TIA > > Ian Smith > -- Hi,

Thanks Larry, much appreciated.  I'll get back to you offline...

Cheers

Ian

postmaster@.............. wrote:
The attached message has been sent to the psn-l mail list.

 Subject: Help! California From: Ian Smith Date: Thu, 22 Jun 2006 07:29:59 +0100 To: psn-l@..............

Hi,

I wonder if there is someone in the group who could help me with a shipping from California pickle I've gotten into.  My DAQ system broke down last week and I've bought a National Instruments daq board from ebay: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=7627538876&ru=http://search.ebay.com:80/search/search.dll%3Ffrom%3DR40%26satitle%3D7627538876%26fvi%3D1

The seller is insisting on using their own packing box instead of a standard Fedex box and this is pushing up the shipping costs to \$173!  If they were to use a Fedex box it would only be \$68.  So, I was wondering if anybody lived close to the seller (Folger Ave.Berkeley, CA 94710 - if you are within walking distance, they have a pickup service), if I could have it shipped to you for onward shipping (USPS or something) and I would reimburse the costs.

Any help would be appreciated.  I've just sent one last email to the seller asking them to use a Fedex box but I'm not optimistic that I'll succeed.

TIA

Ian Smith

--

take a look at the many pages of the web site run by Larry:  http://www.webtronics.com/ ..   I think you'll find most of the answers there.  You may need to get a different geophone than the one you have (if you are right on top of a fault and want to monitor it, then a 4.5 Hz geophone may be suitable.  You'll need an amplifier/filter too of some description.

Hope that helps.

Ian

Kareem from Heyjoojoo.Com wrote:
Just wondering if anyone else was able to help me with my system. I know
that others have similar systems - I recall that someone just recently
obtained a similar system. If you wouldn't mind sharing how you get yours up
and running, I would appreciate it. There aren't many places around where
one can get this kind of information. I'd hate to have to just give it up
but it's not of much value unless it's functioning.

Where can I obtain what I need and how difficult is it to obtain?

Kareem
1.5 city blocks from active trace of N. Hayward Fault segment

-----Original Message-----
From: psn-l-request@.............. [mailto:psn-l-request@..............] On
Behalf Of Jim E ODonell
Sent: Thursday, June 22, 2006 9:43 PM
To: psn-l@..............
Cc: PSN-L@..............
Subject: Re: This system

Hi Kareem-
You can not drive that galvanometer with a geophone- you will need an
amplifier and filter.  The 28 hz will not see anything except freq's higher
than ~20 Hz... Nice Pics tho- <<<  Jim
Jim O'Donnell
Geological/Geophysical Consultant
GEOTECHNICAL APPLICATIONS
702.293.5664 geophysics@.......... 702.281.9081 cell jimo17@........

On Thu, 22 Jun 2006 20:22:43 -0700 "Kareem from Heyjoojoo.Com"
<system98765@.............> writes:

I'm hoping someone can help out with connecting my seismograph drum
recorder system (Photo A, see links below). It's an older model that
was once used in a museum. I do have some basic electrical skills but
unsure how to connect the sensor small geophone (Photo B) with two
leaders. There is a specific part of the system that I'm not sure what
to do what with (Photo C).
If it
looks familiar to you and you can point me in the right direction on
getting it going, please reply. The drum has a power switch and
rotates fine but can't get it to behave like a seismograph system.

Photo A  http://www.heyjoojoo.com/seismo/3 Photo B
http://www.heyjoojoo.com/seismo/4 Photo C
http://www.heyjoojoo.com/seismo/2 Extra photo with alternate view:
http://www.heyjoojoo.com/seismo/1

Kareem Lanier
www.heyjoojoo.com
www.myspace.com/heyjoojoo
37.97 N, 122.30 W

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Subject: ebay auction From: Bob Barns royb1@........... Date: Mon, 26 Jun 2006 09:26:14 -0400 Hi gang, Bison Signal Enhancement Seismograph Item number: 160001366171 ends July 1 I don't know what this is but it looks good. Bob __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: This system From: ChrisAtUpw@....... Date: Mon, 26 Jun 2006 10:23:42 EDT In a message dated 26/06/2006, system98765@............. writes: Just wondering if anyone else was able to help me with my system. I know that others have similar systems. Hi Kareem, If you say what pieces of equipment you are wanting to connect together, you may get some more helpful advice. Do you have a manufacturers, a model numbers and a handbook? Drum recorders have a motor which drives the drum. It may also traverse the drum and / or the pen mounting may move. The pen will probably have a separate drive. The drives may be direct drive, timer motor, servo feedback motor or stepper motor. Which are yours? What are the voltage, current and resistance ratings of the pen drive and which type is it? The oldest types were direct drive, but used a fairly high current. The ? component is a preset variable resistor / potentiometer. It might be used to zero the pen position or to set it's sensitivity. What sort of geophone you are planning to use? The 4.5 Hz ones can be used for local earthquake sensing, but the 1 Hz ones are commonly used for picking up all P and S waves. You can very usefully extend the response of the 4.5 Hz ones down to 0.5 Hz, but this takes a additional amplifier. Drum recorders are more often used for longer period sensors. Larry used to sell all the electronics for a SG seismometer - you just had to add a 1 sec pendulum. It is much easier to analyse the seismic trace on a computer screen. The higher frequency signals are likely to overlap on a drum recorder. You will certainly need a signal amplifier / LP filter and a power supply, but you may also need a high current amplifier to drive the pen. How many pens do you need to drive? Some charts recorders had just one pen, others had three or four. Regards, Chris Chapman On Behalf Of Jim E ODonell Sent: Thursday, June 22, 2006 9:43 PM Hi Kareem- You can not drive that galvanometer with a geophone- you will need an amplifier and filter. The 28 hz will not see anything except freq's higher than ~20 Hz... Nice Pics tho- <<< Jim > anyone can help out with connecting my seismograph drum > recorder system (Photo A, see links below). It's an older model that > was once used in a museum. I do have some basic electrical skills but > unsure how to connect the sensor small geophone (Photo B) with two > leaders. There is a specific part of the system that I'm not sure what > to do what with (Photo C). > The drum has a power switch and > rotates fine but can't get it to behave like a seismograph system. > > Photo A http://www.heyjoojoo.com/seismo/3 Photo B > http://www.heyjoojoo.com/seismo/4 Photo C > http://www.heyjoojoo.com/seismo/2 Extra photo with alternate view: > http://www.heyjoojoo.com/seismo/1
In a message dated 26/06/2006, system98765@............. writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>Just=20 wondering if anyone else was able to help me with my system. I know
tha= t=20 others have similar systems.
Hi Kareem,

If you say what pieces of equipment you are wan= ting=20 to connect together, you may get some more helpful advice. Do you have a=20 manufacturers, a model numbers and a handbook?
Drum recorders have a motor which drives the dr= um.=20 It may also traverse the drum and / or the pen mounting may move. The pen wi= ll=20 probably have a separate drive. The drives may be direct drive, timer motor,= =20 servo feedback motor or stepper motor. Which are yours?
What are the voltage, current and resistan= ce=20 ratings of the pen drive and which type is it? The oldest types were direct=20 drive, but used a fairly high current.
The ? component is a preset variable resistor /= =20 potentiometer. It might be used to zero the pen position or to set it's=20 sensitivity.
What sort of geophone you are planning to use?=20= The=20 4.5 Hz ones can be used for local earthquake sensing, but the 1 Hz ones are=20 commonly used for picking up all P and S waves. You can very=20 usefully extend the response of the 4.5 Hz ones down to 0.5 Hz, but thi= s=20 takes a additional amplifier.
Drum recorders are more often used for longer=20 period sensors. Larry used to sell all the electronics for a SG seismometer=20= -=20 you just had to add a 1 sec pendulum.
It is much easier to analyse the seismic trace=20= on a=20 computer screen. The higher frequency signals are likely to overlap on=20= a=20 drum recorder.
You will certainly need a signal amplifier / LP= =20 filter and a power supply, but you may also need a high current amplifier to= =20 drive the pen. How many pens do you need to drive? Some charts=20 recorders had just one pen, others had three or four.

Regards,

Chris Chapman
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>On=20 Behalf Of Jim E ODonell
Sent: Thursday, June 22, 2006 9:43 PM
Hi=20 Kareem-
You can not drive that galvanometer with a geophone- you will n= eed=20 an
amplifier and filter.  The 28 hz will not see anything except=20 freq's higher
than ~20 Hz... Nice Pics tho- <<< =20 Jim

<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>>=20 anyone can help out with connecting my seismograph drum
> recorder=20 system (Photo A, see links below). It's an older model that
> was o= nce=20 used in a museum. I do have some basic electrical skills but
> unsu= re=20 how to connect the sensor small geophone (Photo B) with two
> leade= rs.=20 There is a specific part of the system that I'm not sure what
> to=20= do=20 what with (Photo C).
> The drum has a power switch and
> rota= tes=20 fine but can't get it to behave like a seismograph system.
>
>= ;=20 Photo A  http://www.heyjoojoo.com/seismo/3 Photo B
>=20 http://www.heyjoojoo.com/seismo/4 Photo C
>=20 http://www.heyjoojoo.com/seismo/2 Extra photo with alternate view:
>= ;=20 http://www.heyjoojoo.com/seismo/1