MAX31856
Production
The MAX31856 performs cold-junction compensation and digitizes the signal from any type of thermocouple. The output data is formatted in degrees Celsius...
Datasheet
MAX31856 on Analog.com
There are 2 situations that could lead to this issue:
1. Soldering: please check if soldering was done properly.
2. Radiation noise within the space: since the input is high impedance when the part is not measuring, external interference is likely to cause OVUV; a 1M-Ohm resistor could be connected to T- to discharge the inteference.
