Digital option

The Blue LED lights up when the digital channel is used.

Thermocouple measurement

After the input filter, the two input lines are directly connected to the MAX31855. This component converts the signal from a type K, J, N, T, S, R or E thermocouple to a digitalized signed 14-bit SPI signal. Have a look how the 14 bits have to be interpreted.

Circuit temperature measurement

Additional to the current temperature on the measuring tip of the thermocouple, the current temperature in the circuit can also to be measured. This 11-Bit measured value has a range from -55 °C to 127°C.

Error handling

If an error occurs in the measuring of the thermocouple, one error bit displays this state and three bits the current error description. These errors are detected:

  • Short circuited to Vcc

  • Short circuited to GND

  • Open (not connected with a thermocouple)