40m QIL Cryo_Lab CTN SUS_Lab TCS_Lab OMC_Lab CRIME_Lab FEA ENG_Labs OptContFac Mariner WBEEShop
  ATF eLog  Not logged in ELOG logo
Entry  Fri Jul 17 11:29:57 2015, Alessandra, Misc, Seismometer, QPD calibration Calibrazione_QPD.JPG
    Reply  Fri Jul 17 11:51:46 2015, Koji, Misc, Seismometer, QPD calibration 
Message ID: 1981     Entry time: Fri Jul 17 11:29:57 2015     Reply to this: 1982
Author: Alessandra 
Type: Misc 
Category: Seismometer 
Subject: QPD calibration 

Yesterday afternoon Koji and I made some measurements to determine the QPD calibration curve.

We used a power supply with a potential difference of 18 Volts as input for the QPD and we looked at the X and Y outputs of the QPD using an oscilloscope. We first centered the beam on the QPD, then we moved the QPD from left to right in a 3 mm range along the horizontal axis using a micrometer, and, in this range, we took 30 measurements of the QPD X output using a digital multimeter. Then we repeated the procedure moving the QPD along the vertical axis and took 30 measurements of the QPD Y output.

I'm going to plot the measurements and to determine the Volts/displacement ratio.

Attachment 1: Calibrazione_QPD.JPG  1.674 MB  | Hide | Hide all
ELOG V3.1.3-