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Entry  Fri Dec 6 17:49:46 2019, rana, Summary, PEM, Jump test of seismometers: EX needs recentering Seismometers.pdfsrc.tgz
    Reply  Sun Dec 8 20:15:41 2019, rana, Summary, PEM, Jump test of seismometers: EX needs recentering seis_all_191208.pdf
       Reply  Mon Dec 9 13:08:24 2019, Yehonathan, Summary, PEM, Jump test of seismometers: EX needs recentering seis_191208.pdf
Message ID: 15083     Entry time: Sun Dec 8 20:15:41 2019     In reply to: 15082     Reply to this: 15086
Author: rana 
Type: Summary 
Category: PEM 
Subject: Jump test of seismometers: EX needs recentering 

I have re-centered the EX (and EY) seismometers. They are Guralp CMG40-T, and have no special centering procedure except cycling the power a few times. I turned off the power on their interface box, then waited 10s before turning it back on.

The fist atm shows the comparison using data from 8-9 PM Saturday night:

  1. there seems to be a factor of 2 calibration diff between the T240 near the BS, and the Guralp seismometers at the end. Which one is right? surpriseWhen was the last time they were cross calibrated?
  2. The low coherence between BS_X and EX_X shows the problem. They should be very coherent (> 0.9) for 0.1-1 Hz.sad

 

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