How can you easily check the PT100 sensor ( using the nominal meter ) if the temperature is known by other device ?

As known the RTD sensors are linear sensors. PT100 is an RTD sensor having100 Ohm at0 C.

Approximately the resistance of the RTD =100 + (0.39*T)

If the temperature is20 C, the resistance of the PT100 will be approximately =107.8 Ohm so that can be checked without special equipment! Just by Ohm meter.

Also rember number of wires2 or3 or4 if rtd3 wire2  terminal are the resistance it, s self it will measure ohms with u "sometimes called compensation terminals" the other terminal will read short circuit with only one terminal 

Don, t forget that cable length will be subtracted from the total resistance