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Entry  Wed Feb 24 16:11:15 2010, Jenne, Update, PEM, Seismic witnesses near MC1 tank moved 
    Reply  Sun Mar 7 23:05:39 2010, rana, Update, PEM, Seismic witnesses near MC1 tank moved seis.png
       Reply  Mon Mar 8 18:15:27 2010, rana, Update, PEM, Styrofoam Cooler on the Seismos SeismometersHuddled.jpg
          Reply  Tue Mar 9 12:06:53 2010, rana, Jenne, Update, PEM, Styrofoam Cooler on the Seismos 
             Reply  Wed Mar 10 15:02:58 2010, rana, Update, PEM, Styrofoam Cooler on the Seismos Seismic-Ref_100310.pngUntitled.gif
                Reply  Sat Mar 13 21:30:22 2010, rana, Update, PEM, Styrofoam Cooler on the Seismos Untitled.png
                   Reply  Mon Mar 15 16:39:36 2010, steve, Update, PEM, Guralp2 centered grlp2ffst.jpg
                      Reply  Thu Mar 18 08:49:51 2010, steve, Update, PEM, Guralp2 centered again ? grlp2xadj.jpg
                         Reply  Fri Mar 19 18:00:14 2010, jenne, Update, PEM, Guralp2 centered again 
                            Reply  Fri Mar 19 21:15:33 2010, rana, Update, PEM, Guralp2 centered again Untitled.png
                            Reply  Fri Mar 19 23:03:41 2010, rana, Update, PEM, Guralp2 centered again huddlez.png
                               Reply  Sun Mar 21 19:25:29 2010, rana, Update, PEM, Guralp2 centered again huddlez.png
                               Reply  Thu Mar 25 09:07:08 2010, steve, Update, PEM, Guralp2 x problem is back grlp2xproblm.jpg
                                  Reply  Wed Mar 31 16:31:44 2010, steve, Update, PEM, Guralp interface box turned off grlpntrfcbxoff.jpg
                                     Reply  Mon Apr 5 01:02:07 2010, rana, Update, PEM, Guralp interface box turned off Untitled.png
Message ID: 2764     Entry time: Mon Apr 5 01:02:07 2010     In reply to: 2743
Author: rana 
Type: Update 
Category: PEM 
Subject: Guralp interface box turned off 

I was checking into the Guralp situation today. I put the rubber balls underneath the granite block (the Q is too high), but found unfortunately that Jenne's styrofoam box is too short to cover the Guralps on top of the granite. If the box was skinny enough to fit on the block or taller by ~6 inches, it would be perfect. We need some new Seismo boxes.

 

Here's the story of the Gur2 noise so far. We need to pull out and repair the breakout box.

1) At some point we noticed that the Guralp2 X channel was behaving badly.

2) Steve tried recentering with just a +12V supply - this didn't work. Jenne then centered it using the +/- 12V supply. This was OK.

3) Around noon on March 24, the channel 'goes bad' again.

4) On the afternoon of the 25th, most of the channels go to zero, but the GUR2X channel stays bad. There's NO ENTRY in the elog about this. This is UNACCEPTABLE. Apparently, the seismometers were disconnected without shutting off the power to the box. You MUST elog everything - otherwise, go home and sit on your hands.

5) On the evening of the 31st, Steve turns off the Guralp breakout box. From the trend, you can see that the signals all go to zero at that time.

6) From then until today, there is no noise in the GUR2X channel. From these tests we can guess that the problem is in the GUR2X channel of the breakout box, but not in the AA Chassis or the ADC, since those showed no excess noise with the box turned OFF. Its hard to be sure without elog entries, but I assume that 3/25-3/31 was a 'seismometer disconnected', but 'box on' state.

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