RTD's reading different temps

[weathejx]

I have the ever popular SYL-2352 and two RTD probes, a 4" and a 50mm and I've got them wired up to the quick disconnects - all from Auber.

I was calibrating the PID and noticed that the probes read the temperature differently, to the tune of 4-5 degrees.

The 4" is reading 32-33 and the 50mm is reading 28-29.

Thoughts? Does it matter if the two red wires are reversed? I.E. when attaching the QDs, the 4" is wired 1-2-3 and the 50mm is wired 3-2-1?

Thanks!

 

[GoodDogShelby]

I have a similar set up. I encountered similar differences but not quite as severe. What I have done is to match up an RTD, Cable, and PID as a set and mark them. When I set them up I set them up in the same combination every time. When I do a 'calibration' check against my Thermopen, I enter an offset into each PID for that combination of RTD, cable, and PID. They hold pretty well when done that way. (Dont' crimp your cables!!!)