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!
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.
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.
I apologize in advance but this needs to be said:
Cold Junction Junction
What's your function
You are invited to finish it.
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.