PSN-L Email List Message
Subject: Re: Got it going I think
From: ChrisAtUpw@.......
Date: Sat, 2 Apr 2005 19:37:10 EST
In a message dated 02/04/2005, 1goss@........... writes:
> I got my Lehman Seismometer up and running I think I may have my gain set a
> bit high, But I think it is ok.
HI Bryan,
It looks like you have a fairly high gain on the amplifier. I suggest
that you examine sections of the trace, do a FFT on it and check to see if the
~six second ocean background is dominant or if there is a lot of other noise.
Try wedging the mass so that it can't move to check on instrument noise? I
can't tell much from the drumplot, since I don't know how it was scaled. It
doesn't show any waveforms or any peak counts. You need to click on X-Scale at the
top of the display and then select 'counts'.
The display shows small deflections during the night, but much larger
ones during the 'working day'. Do you have a lot of traffic / industrial
noise?
What sort of suspensions / bearings are you using? A 12 sec plot
doesn't give you much 'headroom' over the 6 sec microseisms.
Regards,
Chris Chapman
In a message dated 02/04/2005, 1gos=
s@........... writes:
I got my Lehman Seismometer up=20=
and running I think I may have my gain set a bit high, But I think it is ok.=
HI Bryan,
It looks like you have a fairly high ga=
in on the amplifier. I suggest that you examine sections of the trace, do a=20=
FFT on it and check to see if the ~six second ocean background is dominant o=
r if there is a lot of other noise. Try wedging the mass so that it can't mo=
ve to check on instrument noise? I can't tell much from the drumplot, since=20=
I don't know how it was scaled. It doesn't show any waveforms or any peak co=
unts. You need to click on X-Scale at the top of the display and then select=
'counts'.
The display shows small deflections dur=
ing the night, but much larger ones during the 'working day'. Do you have a=20=
lot of traffic / industrial noise?
What sort of suspensions / bearings are=
you using? A 12 sec plot doesn't give you much 'headroom' over the 6 sec mi=
croseisms.
Regards,
Chris Chapman
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