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Message ID: 12621     Entry time: Wed Nov 16 17:07:12 2016
Author: Ashley 
Type: Update 
Category: General 
Subject: Preliminary Microphone Data 

I am currently looking at the acoustic noise around both arms to see if there are any frequencies from machinery around the lab that stand out and to see what we can remove/change.

  • Attachment 1 is a picture of the microphone and suspension system (bungee cords) that hangs from the cable trays to isolate it from vibrations.
  • To record data, I used both the microphone (attachment 1) attach it its preamp connected to a spectrum analyzer in order get a graph of power spectral density, recording from 0-10k Hz and 10-100kHz. I started recording data at the furthest end of the x arm and worked towards the center taking measurements every couple of feet (ten rungs on the cable tray). 
  • The second attachment is the first 5 psd I got from the furthest end of the x arm going 10 rungs on the cable tray closer each measurement.
  • Going forward, I am going to take more measurements with greater resolution at the lower frequencies from 0-200 and stepping up from there by factors of 2.

IMG_0171.JPG

Attachment 1: first_PSD_12kHz.pdf  43 kB  | Hide | Hide all
first_PSD_12kHz.pdf
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