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Entry  Thu Feb 4 14:05:59 2010, Aidan, Electronics, Ring Heater, Ring heater transfer function measurement 240mHz-5Hz 
    Reply  Thu Feb 4 15:26:37 2010, Aidan, Electronics, Ring Heater, Ring heater transfer function measurement 240mHz-5Hz 
Message ID: 7     Entry time: Thu Feb 4 14:05:59 2010     Reply to this: 8
Author: Aidan 
Type: Electronics 
Category: Ring Heater 
Subject: Ring heater transfer function measurement 240mHz-5Hz 

I've been trying to measure the ring heater transfer function (current to emitted power) by sweeping the supply voltage and measuring the emitted power with a photodector positioned right next to the ring heater.

Last night the voltage was sweeping with a 1000mV setting on the SR785 which was fed into the Voltage Control of the Kepco Bipolar Operational Power Supply/Amplifier which was biased around 10V.

The results are very, very strange. The magnitude of the transfer function decreases at lower frequency. I'll post the data just as soon as I can (ASCII dumps 13 and 14 on the disk from the SR785).

The circuit looks like this:

 

SR785 drive ----> Amplifier ----> Ring Heater : Photodetector ---> SR560 (5000x gain) ----> SR785 input

 

 

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