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
Entry  Sat Aug 18 19:29:56 2012, Den, Update, PEM, EM 172 microphones noise  em172.png
    Reply  Mon Dec 3 16:37:09 2012, Steve, Update, PEM, EM 172 microphones ordered 
Message ID: 7226     Entry time: Sat Aug 18 19:29:56 2012     Reply to this: 7777
Author: Den 
Type: Update 
Category: PEM 
Subject: EM 172 microphones noise  

I've put EM 172 microphones inside Steve's isolation box to measure their noise. I've attached mics to each other and aligned them using the tape.

At low frequencies (below 1 Hz) the noise is limited by ADC as there is a 10 Hz high-pass filter inside mic readout box.

ADC noise is measured by splitting the signal from 1 mic into 2 ADC channels.

em172.png

ELOG V3.1.3-