Gil, Do you mean ACCURACY or RESOLUTION or PRECISION ?

You can get almost any resolution you want, but a thermocouple is precise to only around 75mK. A PRT is much higher precision, certainly precise to 5mK or better.

Thermocouples can be used to over 1500 C, with exotic junctions. PRTs are noto used over abot 500 C. too much problem with alloying with he materials of construction.

I would rather read a PRT than a thermocouple, but they do different jobs in the limit.

Analog devices do an excellent signal conditioner for thermocouples.

Best wishes

Steve

Steve