USB2416 : thermocouple readings noise issue

[rakeshaashay]

We are using USB2416 with thermocouple.

But it is showing erratic readings.  how to resolve this issue?

[JRys]

Could you ensure the USB-2416 channel is configured to use a Data Rate of 50 or 60 Hz, depending on the power grid frequency? 

[rakeshaashay]

We have checked by changing the settings, but still there are issues with noise in the data.

Do we need to check any settings or hardware connections of the USB2416.

 

[JRys]

You can check the hardware by removing all your signal connections, including the grounds, and connecting a short wire across the input terminals. This will simulate a thermocouple close to ambient temperature. Do this on the channels you are using for temperature. Acquire some data and verify the readings are stable, usually within a few degrees of ambient. Next, replace the wire on one channel with one of your thermocouples and acquire some data. If the temperature is stable, connect a second thermocouple. You may have a ground loop if the second thermocouple makes the first one noisy. This is usually caused by connecting the grounded thermocouple end to a metal object. On the other hand, your thermocouple could be inside an electric oven, and switching heating elements causes a non-50/60 Hz noise, which gets through our low pass filter algorithm. In either case, you may want to consult an expert with thermocouples to help troubleshoot.