Temperature Transmitters, temperature sensors,RTD, PT100 A temperature transmitter is a device that connects to a temperature sensor to transmit the signal elsewhere for monitoring and control purposes. Typically, the temperature sensor is either an RTD(PT100 or PT1000), thermistor or thermocouple type sensor and will interface with a PLC, DCS, data logger or display hardware. The temperature transmitter's role is to isolate the temperature signal, filter any EMC noise, amplify and convert the temperature sensor's signal to a 4-20mA or 0-10V DC range for further use.