Thermocouple Not Reading Correctly

[WhiteKnight]

I have 3 K-type thermocouples attached to a USB-9211A device using the LabVIEW-provided CJC constant. I'm using it to measure the temperature of a hot water bath for a period of days and after about 6 hours LabVIEW didn't read from the thermocouples anymore and put up a 0.0 value on the indicators. What could the problem be?

[smercurio_fc]

That implies that an error occurred somewhere. Do you have error handling in your code?

[WhiteKnight]

I used the simple error handler, but I didn't see an error. I just stopped and restarted the VI and it started working again, but it happened again hours later.

[Corby_B]

Hello WhiteKnight,

Thanks for your post!

I see that you are reading 0 for a temperature after hours of operation. I would tend to agree that there could be an error here since the reading is going to 0. When you call your DAQmx read how many samples are you reading at that moment in time? Are sampling at the fastest rate of 12 S/s? If you could perhaps post a screen shot of your code we might be able to see if something is amiss here. Let us know if you are still seeing the issue.

Cheers!

Corby_B

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