We highly recommend to only use MET148 with sensors mentioned in the manual.
This is to prevent damages to the MET148 and losing the accuracy level.
Since the Sepam 40 devices do not support PTC probes directly, it is necessary to use a converter which emits digital outputs for annunciation/tripping.
This digital data is then connected to Sepam digital inputs for tripping
I know some Thermistor protection relays from the Télémécanique trend mark and advise you the following reference LT3-SA or LT3-SM.