MCP9600 + Braided thermocouple not sensitive enough


I’ve recently purchased MCP9600 breakout and Braided thermocouple. I’ve installed it on a PI with the i2c baud rate decreased to 40,000. To test, I’m using the Python example from the Github page

The hot and cold junctions read the same at room temperature (20 C)

When placed against a heat source, the hot junction does not seem sensitive enough. Pressed against a mug of tea, it only reads 42C while my IR thermometer says 60C!

Have I missed a step to calibrate the thermocouple?


TLDR: dropped the i2c baud rate to 9600. Now readings are within 5 C.

At 40,000 baud: it was reacting to heat, but the get_temperature_delta was giving erroneous readings.

At 20,000 baud: within 10C of my IR thermometer. get_temperature_delta function gave correct readings.

At 9600 baud: within 5C of my IR thermometer. get_temperature_delta gave correct readings. Bonus: readings were faster to reach “stable” point.