Hi guys,

I just bought a chinese K type temp sensor (up to 1200 C) for measure the retarder temp, it's connected to the box's temp input and works well until the sensor's metal case not touched to the retarrder or any metal part of the roller.

The retarder, roller chasis, YD box (an all metal thing..) connected to the mains' earth. (currently I have no any EMI problems, every signal are clean and noise free)

This also happened if everything are turned off, except the YD box.

I measured the +/- pin of the sensor agains the metal case/wire and no  any conenction between them...

Any idea ?