Thanks George,
I'm pretty sure that I am using a T type thermocouple (they are labelled 'T' Type) and a T type board (the chip is suffixed 'T'). I've tried several makes of T type thermocouple, all give the same result, so I suspect the board.
Kit:
Black Box Tech MAX31855 T Type breakout board, details here:
T Type thin wire Thermocouple:
Curiously I've just noticed that increasing the temperature of the MAX31855T (by putting my finger on it) increases the reported temperature of the thermocouple too - to the correct temperature of the room. I'll try this when I get back in the lab with some liquid N2.
Im waiting for the postman to deliver some new 'Playing with Fusion' T type boards, so we'll see how those work.
Thanks for posting...