PSN-L Email List Message
Subject: Re: Counts
From: Barry Lotz barry_lotz@.............
Date: Wed, 29 Apr 2009 19:20:21 -0700 (PDT)
Ted
2 cents:
The late Sean Thomas Morrissey emailed PSN on Nov 13, 1999 with expected se=
ismograph output. He related amplitude,magnitude and distance.Using his dat=
a I plotted distance on the x axis, my vertical sensor count on the y axis =
and had lines for 0.5 magnitude incriments from 3 to 8. It was plotted on a=
log-log scale.My particular sensor was theoretically 2000v/m/s @ 5 vts=3D3=
2768 cnt. I then plotted individual points for each actual event I recorded=
.. It correlated pretty well. The four corners of my graph were: Clip @ M4.5=
@100km, and M8 @ 14000km. My winter microseism amplitude was about 300 coun=
t. This related to M2.5 @ 100km and M6 @ 14000km. I like the idea of record=
ing at two or more gains simultaneously and after reviewing the data, savin=
g the best.=20
Barry
--- On Wed, 4/29/09, tchannel wrote:
From: tchannel
Subject: Counts
To: "psn"
Date: Wednesday, April 29, 2009, 8:02 AM
=20
=20
Hi Folks,=A0 I have two vertical sensors in=20
test, both using Larry's one channel board and DATAQ adc.=A0=A0 One of the=
=20
boards is set for low gain and one is set for high gain, using the=20
jumper.
=A0
The first earthquake records was the 5.6m in Mexico=20
April 27th.=A0=A0 Not unexpected the counts on the one using high gain was=
=20
10x the one using low gain.=A0=A0 Something like 70 vs 700.
=A0
Both traces looked fine and I could see little=20
different, aside for the counts.=A0=A0 My question is what should my count=
=20
target be?=A0=A0 Someone may have indicated about 100 to 300=A0counts=20
during the quiet of night?
=A0
The reason I ask is I see data files posted with=20
many using higher counts 700 or 800, instead of smaller=20
numbers.=A0=A0=A0 I know the higher gain feature on the board is for=20
lower voltage output.=A0=A0 My coil and magnets are similar to Chris's=20
quad magnet arrangement, and a coil of 4000 turns, so I have plenty of=20
voltage.
=A0
I would like your opinions and why.
=A0
=A0
Ted 2 cents: The late Sean Thomas Morri=
ssey emailed PSN on Nov 13, 1999 with expected seismograph output. He relat=
ed amplitude,magnitude and distance.Using his data I plotted distance on th=
e x axis, my vertical sensor count on the y axis and had lines for 0.5 magn=
itude incriments from 3 to 8. It was plotted on a log-log scale.My particul=
ar sensor was theoretically 2000v/m/s @ 5 vts=3D32768 cnt. I then plotted i=
ndividual points for each actual event I recorded. It correlated pretty wel=
l. The four corners of my graph were: Clip @ M4.5@100km, and M8 @ 14000km. =
My winter microseism amplitude was about 300 count. This related to M2.5 @ =
100km and M6 @ 14000km. I like the idea of recording at two or more gains s=
imultaneously and after reviewing the data, saving the best.
Barry<=
br>--- On Wed, 4/29/09, tchannel <tchannel@............>
wrote:
From: tchannel <tchannel@............
t> Subject: Counts To: "psn" <psn-l@..............> Date:=
Wednesday, April 29, 2009, 8:02 AM
=20
=20
Hi Folks, I have two vertical se=
nsors in=20
test, both using Larry's one channel board and DATAQ adc. One o=
f the=20
boards is set for low gain and one is set for high gain, using the=20
jumper.
The first earthquake records was the 5=
..6m in Mexico=20
April 27th. Not unexpected the counts on the one using high gai=
n was=20
10x the one using low gain. Something like 70 vs 700.
Both traces looked fine and I could se=
e little=20
different, aside for the counts. My question is what should my =
count=20
target be? Someone may have indicated about 100 to 300 cou=
nts=20
during the quiet of night?
The reason I ask is I see data files p=
osted with=20
many using higher counts 700 or 800, instead of smaller=20
numbers. I know the higher gain feature on the board is f=
or=20
lower voltage output. My coil and magnets are similar to Chris'=
s=20
quad magnet arrangement, and a coil of 4000 turns, so I have plenty of=20
voltage.
I would like your opinions and why.
Thanks, Ted
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