T Thermocouple transmitters. Scaled 0 to 50 Deg C temperature input & 4-20mA output. Also available scaled as alternate temperature spans.
A thermocouple is a low cost flexible temperature sensor.
Bare Bead Thermocouples
The thermocouple transmitter converts the thermocouple voltage change to 4-20mA current change. The 4-20mA signal allows the thermocouple , when using a thermocouple transmitter, to be connected to a PLC. This allows thermocouples to be used as a part of a modern control system.