Cold junction calibration

[PurelyNonsense]

Just thinking about methods to calibrate the lab junction. We have a junction wire that we calibrate. We have a procedure to calibrate thermocouples using the junction. What I was thinking, and I believe this is how I did it before, is as follow:

• Connect the meter connector to a 3458A.
• Place junction in the ice/liquid bath
• Place RTD with the junction as close as possible
• Connect the other side of the probe to a 5720A
• Source 0 mV to the thermocouple
• Take mV reading from 3458A and temp from the RTD
• Convert mV to temp

Let me know if that seems to work. I have very little guidance on this subject and could use some advice. Thanks!

[bAdbOb]

If you are interested in more information: ASTM E2730, "Standard Practice for Calibration and Use of Thermocouple Reference Junction Probes in Evaluation of Electronic Reference Junction Compensation Circuits" describes your method to calibrate reference junctions.

[PurelyNonsense]

Thanks for the advice but I don't really want to pay for the document. Our lab cannot buy it (military lab) and I sure as heck am not buying it on my own. I just wanted to know if I was correct in my assumption or if I needed to figure out a different method. The last guy who did the calibration is not here anymore.

[Bryan]

I apologize in advance but this needs to be said:
Cold Junction Junction
What's your function

You are invited to finish it.

[briansalomon]

If your technical library doesn't have the procedure you may be able to get GIDEP. I have 33K5-4-296-1 and 33K5-4-322-1.

I believe the purpose of the thermocouple reference junction is to provide a zero reading for a temperature reading instrument designed to use thermocouple sensors and to provide a micro/millivolt input to that device referenced to the zero established from the ice bath.

You need the procedure.