Originally Posted by Malintent
I know how to calibrate.. not a problem. My concern is the amount of offset. 13+ degrees seems excessive. It reads higher than actual (it needs a -13 offset). It is a pt100 RTD on a cheap Auber PID (both bought from Auberins). I cut the very ends of the probe wire off to remove the terminal connectors, then soldered it to a 3 prong socket (also from Auber).
My question is, should I be concerned that this is indicative of a poor solder joint (higher resistance = higher indicated temp), a bad probe, or is an initial 13 degree error on par for what you guys have seen with these?
No.. that seems bad. My cheap chinese RTD has an error of 1.5*F. My even cheaper chinesier probe that ended breaking on me had an error of 3.1*F.
I would think that one from Auber should be pretty damn close to correct.
Did you test the probe with the PID before you cut and soldered through the connector?
The soldering shouldn't be causing you a problem unless your work was really crappy one wire and not the others. The whole point of the RTD's having three wires is to compensate for the resistance in any leads and connectors on the path between the probe and the device using the probe.
If you didn't check it at first with probe directly connected to PID, it might be worth the effort to unsolder the thing and test it directly connected.
13*F seems too much of an error to me, but I AM NOT AN EXPERT.