40m QIL Cryo_Lab CTN SUS_Lab TCS_Lab OMC_Lab CRIME_Lab FEA ENG_Labs OptContFac Mariner WBEEShop
  40m Log  Not logged in ELOG logo
Message ID: 6594     Entry time: Wed May 2 21:04:06 2012
Author: Den 
Type: Update 
Category: PEM 
Subject: EM 172 coherence 

I measured coherence between 2 EM 172 microphones in a "quiet room" with SR785

em_coh.png

High-frequency noise (>2k) is SR785 noise - I'm not using any amplifier now, the signal from microphone is sent directly to SR785 and is weak at high frequencies.

ELOG V3.1.3-