There are also many battles out he=
need fighting in addition to getting the last nanometre resolu=
from a home-brew seismometer.
Thanks for the feedback and for your differen=
Sure, but my Email was not primarily concerne=
trying to get the last nanometre of sensitivity, but with whether the thin=
works at all !
Will the detection of only one earthquake a=
when it could and should be several every WEEK, either spark or=
maintain any significant interest in any of your kids? This seems more tha=
bit unlikely to me.
And encouraging someone to make a considerabl=
effort to build equipment which then doesn't work will definitely kill=20
off ANY interest !
Quote: "Do your homework! A lot of folks out there have already done=
save yourself time, effort, and money by doing some research."
So what 'fruits' of caveman's 'research'=
have actually made it through to the design?
A very noisy, non linear photo detector was=
A highly temperature dependant photo emitter=
chosen The excitation current was neither stabilised nor temperature=20
A single ended electronic construction was ch=
which does not reduce any common mode effects
A multi filament suspension was chosen
No details of how to design the sensor to mat=
frequency range of seismic signals seems to be given
No details of how to design and adjust=
damper to give 0.7 critical damping seems to be given
Getting adequate seismic detection=20
sensitivity is not normally a problem with optical, electromagne=
magnetic or capacitor sensors, in my experience. I welcome equipment and=
suggestions which work.
Note that caveman had detailed drawings of a=
Anderson seismometer available to copy / inspire him. Richter used several=
seismometers to develop his Earthquake Magnitude Scale in 1935, so we can=
that they worked reasonably well.
For the past nine years I have=
involved with a regional science fair and have not seen a single seismom=
So, having identified one of the problems,=20
can YOU help correct it, please? Is this simply because the stud=
download a list of project suggestions and seismometers are just not=
Provide information sources and design help? Maybe publicise som=
seismic projects which actually DO work? Put them on psn?
I had one highschool tea=
cher who let=20
me operate my Lehman from her classroom for a couple weeks each year =
now she is gone and there is zero interest in seismology in the area. From=
I sit there will not be any new seismologists to use those last bits of=20
How have you been trying to get kids interest=
Anyone providing a spark of ima=
an avenue of entry for interested young minds is making a great contribu=
to seismology or more broadly science. Earth science is falling ou=
classroom time in favour or green and alternative energy. =20
NOT around OUR neck of the woods!! A goo=
quality working Lehman was designed for schools and marketed from Easter=
Sales since then have exceeded 400 systems. This is a successful project=
we expand further into Europe next year. See http://www.bgs.ac.uk/schoo=
click on 'Seismometers'.
Remember that we have just 1/5 the population=
I would be quite happy to pass on some detail=
the design. There is a handbook on the website. There is considerable enth=
amongst our pupils for 'Real Science with Real Seismic Signals'. It is 'th=
seismometer and small interested groups run it, analyse the quakes with he=
from AmaSeis, plot them on a world map and keep records. They also ge=
considerable credit for having done a practical scientific project wh=
they apply for a place at University.
What will give a student more=
motivation, connecting a professional device with no understanding=
it or constructing a caveman device and recording a distant quake?&=
We are up against Facebook and IPhones for kids time and energy.<=
What professional devices are you considering=
Are you suggesting that it is not possib=
make a good quality DIY seismometer?
Where is the evidence that the cave=
device can give an even marginally adequate performance?
One quake a month (maybe) will not provide mu=
competition for Facebook or an IPhone, but it might generate a=
A few years back, I helped one of your studen=
with his seismic project - very long range help! We discussed the design=
requirements, principles and details. He had a friend helping with some=20
machining, but made the design choices himself. He produced a good wo=
seismometer and a full written account, complete with recordings of=
and comparison records from a local broad band seismometer. They were almo=
identical. He entered this in a Science Fair and won a First Prize.=
You need many more like him.
What you do seem to be lacking in the USA is=
inexpensive school seismometer responding flat with velocity from about 5=
20 seconds. The response must be independant of temperature. It must be ea=
set up and operate. Iris seem to be insisting on a vertical sensor.=
would be preferable if it was compensated for variations in air pressure,=
these are the predominant source of sensor noise.
What do you suggest?