PSN-L Email List Message

Subject: Re: Counts
From: Robert McClure bobmcclure90@.........
Date: Wed, 29 Apr 2009 13:02:29 -0400

Hi Ted,

  I use the 12-bit Dataq DI-154 for data acquisition. I aim for about
100 microns per second for full scale output. To find out what is the
corresponding gain value to use to obtain this requires calibration of
your sensors. Please see my web page for my calibration

  Also, for short-period amateur vertical sensors, inverse filtering
is very advantageous for obtaining longer period response. See my web
pages for discussion of inverse filtering and download of  the
WQFilter utility program for inverse filtering of WinQuake files.


On 4/29/09, tchannel  wrote:
> Hi Folks,  I have two vertical sensors in test, both using Larry's one
> channel board and DATAQ adc.   One of the boards is set for low gain and one
> is set for high gain, using the jumper.
> The first earthquake records was the 5.6m in Mexico April 27th.   Not
> unexpected the counts on the one using high gain was 10x the one using low
> gain.   Something like 70 vs 700.
> Both traces looked fine and I could see little different, aside for the
> counts.   My question is what should my count target be?   Someone may have
> indicated about 100 to 300 counts during the quiet of night?
> The reason I ask is I see data files posted with many using higher counts
> 700 or 800, instead of smaller numbers.    I know the higher gain feature on
> the board is for lower voltage output.   My coil and magnets are similar to
> Chris's quad magnet arrangement, and a coil of 4000 turns, so I have plenty
> of voltage.
> I would like your opinions and why.
> Thanks, Ted

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