We are experiencing real problems trying to measure & log temperatures produced on an ultrasonic Generator PCB. We have taken the precautions detailed in other posts regarding good earthing but without success. We are using standard type K thermoucouples.
I am assuming that the problem is due to pick up from various parts of the circuit - (there are inductors & transformers & MOSFETSon the PCB)
If i connect channel 1 only, all is well. As soon as another thermocouple is connected to any of the other channels the temperature readings become unstable & incorrect.
Is there a way round the problem - can you get screened thermocouples?
Hope someone can help