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Message ID: 2372     Entry time: Mon Jul 22 22:01:28 2019
Author: ScottA 
Type: DailyProgress 
Category: TempCtrl 
Subject: Differential Temperature Sensing Experimental Setup 

Differential Temperature Sensing Setup:

This experiment consists of a thermally insulated box that contains a large piece of copper and 3 AD590 temperature sensors thermally pasted together using Thermalloy Thermal Joint Compound 249. The AD590s are connected to a temperature sensing circuit (DCC: https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?.submit=Identifier&docid=D1800304&version=) within a metal box which is also contained in a larger insulated container. This circuit is powered by an external 15V supply (DCC: https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?.submit=Identifier&docid=D1000217&version=). The output of the temperature circuit is connected to an ADC General Standards 16AI64SSA. I use 6 channels of the ADC, Ch. 0 1 and 3 records the AD590 temperature data, Ch.2 I short to ground and record the referred input voltage noise of the ADC, Ch.4 is the positive pin of the 15-volt power supply while Ch.5 is the negative pin. The ADC has a maximum readout of plus or minus 10V so to bring the 15V supply into the measuring range I used a 1.1k to 1.1k voltage divider on both pins to reduce the voltage reading by half.

Goal:

I want to take the difference of each channel with the other channels to pull out the noise for each sensor. As well as get the noise from the 15V power supply and the ADC using channels 4/5 and 2. Then I will use this data to better estimate the noise budget of the setup as a whole, and to compare the prediction to reality.

Attachment 1: Diff_Temp_Setup_Pics.zip  23.988 MB  Uploaded Tue Jul 23 00:52:39 2019
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