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Message ID: 2791     Entry time: Wed Jun 29 09:39:01 2022
Author: Clare Nelle 
Type: DailyProgress 
Category: Emissivity testing 
Subject: RTD Calibration Day 2 

[Radhika, Hiya, and Clare]

We debonded the RTDs from the chamber using isopropanol and acetone, then soaked the RTDs in isopropanol for about 15 minutes to remove residue. We then took resistance measurements in ice water detailed below:

Ice Water Calibration Measurements (completed 28-06-2022):

1) Prepared ice water bath by filling beaker with crushed ice and then water to one half inch below the ice surface. Let the ice bath sit for about 1 minute. 

2) All six RTDs were measured (labeled A-F). For each RTD, the resistance in the ice water bath was measured by swirling the RTD held by the DMM leads in the water until the DMM readout stabilized. 

3) These measurements were repeated in the reverse direction (Started with RTD F).

*Note: in the process of ice bath calibration, RTD D broke. 

RTD Trial 1 (\Omega) Trial 2 (\Omega)
A 100.2 100.15
B 100.15 100.3
C 100.1 100.1
D X X
E 100.1 100.1
F 100.1 100.1

Liquid Nitrogen Calibration Measurements (completed 30-06-2022):

Procedure: We clipped the DMM leads to the RTDs and taped the two clips together. This is very secure - good method for the future. We dipped the taped clips with the RTD into the LN2, and swirled under the liquid surface until the DMM readout stabilized. We only took one set of measurements because we are very confident of the boiling point of N2. 

*Note: RTD A broke. This is because we spread the RTD wires out to put into the aligator clips, making them very prone to snapping when we move them. This means that we do not have an RTD on the cold head.

Results (ohms):

A: X

B: 19.8

C:18.2

E:18.5

F:19.8

Attachment 1: ice_bath_calibration.xlsx  9 kB  Uploaded Wed Jun 29 11:08:56 2022
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