FP-TC-120 data swinging all over

[bdwhaley]

See attached file that shows 4 temperature trend lines. They start out totally stable. Then two of them go crazy. This happens on multiple machines

[pravin b]

Whale,
What do you have connected to those two temp channels? Since two of the four lines are still good i would think the module is still functioning fine. Since two of the lines that go crazy begin well and stay good for a while, i don't think anything on the internal circuitry of those channels is in question.

Have you tried connecting those two temp inputs to some other channel inputs on the same module? Knowing if the bahavior follows the inputs or the specific channels on the module could be helpful too.

Regards,
Pravin

[Rainer Ehrt]

Hi Whale


> See attached file that shows 4 temperature trend lines. They start out
> totally stable. Then two of them go crazy. This happens on multiple
> machines

to me it looks like wrong extensioncables and / or wrong (srew)- connectors
acting as additional thermocouple in series with the one that you're measuring
with. Since you monitor these crazy temp drifts of about 30°C, this could be
the temp of a motor, or a lamp shining on the connection terminal of your
(wrong) thermocouple extension cable.

Or maybe there is moisture somewhere and you don't use isolated thermocouples?

Hope this helps,

Rainer