I hope this is a proper place to ask the question. I am using two different methods to do a thermal measurement on a flyback power supply that has a planar transformer. First I used FLIR E60 thermal camera and then I did the measurement with OMEGA thermocouples.
My problem is that with thermocouples I obtain temperatures of about 10 degC lower compared to thermal camera. To attach the thermocouples I used a sort of adhesive pads in which I stick the thermocouples.
Did anyone experience anything similar or my method is wrong? To which measurement method can I trust more? My next step would be maybe to stick the thermocouples to my points of interest with a kapton tape (perhaps).
Best Answer
Using thermocouples on switching power supplies is often tricky because of the EMI. Wire loops of the thermocouples tend to pick up noise of the converter and measurements are messy. Try to switch off the converter and check if the readings of the thermocouples don't change apruptly (which would indicate EMI issues).