I'm currently trying to use a K thermocouple connected to an Arduino Therm shield. Using official Therm shield library, temperature values display in serial interface, but values aren't accurate for this kind of sensor, fluctuating from 25°C to 35 °C. Current ambient temperature is around 30°C, but it doesn't stabilize, I've tested my K thermocouple with a dedicated multimeter, confirming thermocouple was stable and OK. I've also tested another Therm shield, that gives the same results, and finally tested with another K thermocouple, which isn't the same as the first one (new reference), with the same result.
Looking for some information on the internet, I've read that MAX31855 component stability could be improved by adding a capacitor betwwen mesuring entries, but it doesn't improve the quality of my displayed values.
Does anyone have encountered similar troubles?