I just installed a couple of them into my system tonight. One of them is showing that the coolant temp is actually going up (compared to the value from the D5 Next on the same loop) as it goes through the radiator. I'm guessing this is not correct.
Is there a good way to recalibrate these sensors?
The temp sensor in the MPS 400 does not make direct contact with the liquid in the system and from my experience always read a higher number than the actual water temp.
My suggestion is to ditch the MPS 400 and take a look at the High flow USB sensor, it is the most accurate flow sensor you can get and it does not need any calibration on your part.