rakeshaashay Posted December 6, 2023 Share Posted December 6, 2023 We are using USB2416 with thermocouple. But it is showing erratic readings. how to resolve this issue? Link to comment Share on other sites More sharing options...
0 DAQman Posted December 6, 2023 Share Posted December 6, 2023 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? Link to comment Share on other sites More sharing options...
0 rakeshaashay Posted December 8, 2023 Author Share Posted December 8, 2023 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. Link to comment Share on other sites More sharing options...
0 DAQman Posted December 8, 2023 Share Posted December 8, 2023 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. Link to comment Share on other sites More sharing options...
0 rakeshaashay Posted May 29 Author Share Posted May 29 Still we are facing issue of noise with thermocouple channels. Do we need to ground the USB2416 system and AI-EXP32? How to ground the system? We have minimised the sampling rate to 2.5Sec but still there is noise. please let us know the diffrent techniques to remove the noise. Please reply urgently Link to comment Share on other sites More sharing options...
0 DAQman Posted May 29 Share Posted May 29 Did reducing the system to one thermocouple and the rest using a wire-short result in smooth or noisy data? If it's noisy, do you have additional sensors besides thermocouples? Do you use grounded or ungrounded thermocouples? Link to comment Share on other sites More sharing options...
0 rakeshaashay Posted May 30 Author Share Posted May 30 The sensors are ungrounded. In all cases data is noisy. How to eliminate the noise? Link to comment Share on other sites More sharing options...
0 DAQman Posted May 30 Share Posted May 30 The USB-2416 can eliminate 60 Hz noise (Data Rate = 60). If your application involves electric ovens and kilns, I want you to know that many of them use sophisticated electronics that repeatedly switch heating elements. These tend to generate non-60 Hz noise, which is not rejected by our filter algorithm. For applications like these or similar ones, we suggest using a thermocouple signal conditioner with an analog low-pass filter like the 8B47 series from www.dataforth.com. Link to comment Share on other sites More sharing options...
0 rakeshaashay Posted May 31 Author Share Posted May 31 Do I need to ground the system? How to ground? External signal conditioner is not the solution Link to comment Share on other sites More sharing options...
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rakeshaashay
We are using USB2416 with thermocouple.
But it is showing erratic readings. how to resolve this issue?
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