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JLD612 and PT100 RTD
Posted: Wed Mar 04, 2015 6:55 pm
by gmc8757
Hello, I ordered these two items, I got them set up fairly easy but the temperature reading seems to be quite a bit higher than it should be. I tested it by comparing its reading to a few different dial thermometers. The dial thermometers were consistent but the JLD612 and PT100 were not.
Any suggestions on how to get it to read correctly?
Thank you
Re: JLD612 and PT100 RTD
Posted: Fri Mar 06, 2015 11:38 am
by Tech_Marco
There is offset you can fine tuned it. Check with the manual
Marco
Re: JLD612 and PT100 RTD
Posted: Fri Mar 06, 2015 12:57 pm
by gmc8757
Any idea how to do that?
I'm not getting it from this manual.
http://mythopoeic.org/misc-files/JLD612_Manual.pdf
Re: JLD612 and PT100 RTD
Posted: Sun Mar 08, 2015 10:32 pm
by richiem
How far off does it seem to be? Are we talking a degree or two, or tens?
Re: JLD612 and PT100 RTD
Posted: Mon Mar 09, 2015 4:08 am
by gmc8757
At 150f it was reading about 175
At 55f it reads about 70
So quite a bit
Re: JLD612 and PT100 RTD
Posted: Tue Mar 10, 2015 11:06 am
by richiem
Yep, that's a lot -- I suspect that either the Pt100 RTD probe is bad, or the JLD612 has a problem. Talk to Marco.
If you have a digital ohmeter or a good quality DMM, stick the probe into a slurry of crushed ice and water, and measure the resistance between one red wire and the blue wire -- it should be very close to 100 ohms. if it is off by quite a bit, say 10 percent, then it needs to be replaced. You can check the other end of the scale by immersing it in rapidly boiling water, if you are near sea level (<1000' above) -- the nominal value should be 138.5 ohms; again an error of 10% or more is an indicator of a bad probe. The resistance of the red and blue wires should be a small part of the total (<0.5%), so it can be ignored.