JLD612 and pt100

joeo
Posts: 4
Joined: Wed Mar 25, 2015 11:14 am

JLD612 and pt100

Postby joeo » Wed Mar 25, 2015 11:31 am

I've combed through the posts and sort of found stuff but not quite.

currently testing out the 612 and pt100 probe. everything is wired properly, settings are set to correct probe. I am going to use this setup to control heating an air bath that uses an old commercial coffee pot with a heating element at the bottom. I did adjust hyst to 1 and probe to 10.0 for better resolution.

I initially did a run where I set the temp at 125F and used a amprobe k type to confirm temps. I clipped the k type to the pt100 to keep temps similar. at 125f, there was no variation and I did not autotune. since my system will run at two different temps, 155c and 195c, I reset the temp to 155c and when it got to desired temp, I autotuned and then had to adjust the input offsest by -32c.

changing the temp to 195c, I am under by -15c.

from what I'm reading, I shouldn't have this much correction required. suggestions?

Tech_Marco
Posts: 4310
Joined: Mon Jun 15, 2009 3:00 pm

Re: JLD612 and pt100

Postby Tech_Marco » Wed Mar 25, 2015 11:36 am

You may need to run the Auto tune in closed loop system. That said, you need to power it up and let it Auto tune for hrs or it may take up to 24hrs depends on the complexity of the location.

Plus, make sure the PT100 probe is totally submersed in water, only the tip can be wet


Regards,
Marco

joeo
Posts: 4
Joined: Wed Mar 25, 2015 11:14 am

Re: JLD612 and pt100

Postby joeo » Wed Mar 25, 2015 12:53 pm

Tech_Marco wrote:You may need to run the Auto tune in closed loop system. That said, you need to power it up and let it Auto tune for hrs or it may take up to 24hrs depends on the complexity of the location.

Plus, make sure the PT100 probe is totally submersed in water, only the tip can be wet


Regards,
Marco



sorry, should have clarified it...is being run in a closed loop setup. autotune was only taking 10-15 minutes. would calibrating probe in water (boiling or ice water) provide more accuracy?

am i running autotune in boiling water? or simply adjusting the discrepancy?

joeo
Posts: 4
Joined: Wed Mar 25, 2015 11:14 am

Re: JLD612 and pt100

Postby joeo » Wed Mar 25, 2015 1:22 pm

testing with boiling water, my amprobe reads 212.5 and the 612/pt100 reads 212.3 with -17.4 correction. both probes are set in a big pot of water with probes sitting about 1" under the water so that there is about 4-6" of space between them and the bottom of the pot. neither probe is touching each other.

Tech_Marco
Posts: 4310
Joined: Mon Jun 15, 2009 3:00 pm

Re: JLD612 and pt100

Postby Tech_Marco » Wed Mar 25, 2015 2:11 pm

Then the probe could be defective. Did you reverse the two blue wire for testing? Give it a try see if it could fix t. If not, email "Contactus@lightobject.com" for a replacement


Marco

joeo
Posts: 4
Joined: Wed Mar 25, 2015 11:14 am

Re: JLD612 and pt100

Postby joeo » Wed Mar 25, 2015 3:59 pm

I'll try that when i get home

richiem
Posts: 270
Joined: Mon Jan 03, 2011 3:47 pm
Contact:

Re: JLD612 and pt100

Postby richiem » Thu Mar 26, 2015 2:54 pm

In a recent previous post, I explained how to check the Pt100 probe with ice water and boiling water using an ohmmeter (DMM) -- this lets you know whether it is the probe or the 612 that has the problem. Could be either, so knowing which is kind of important.


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