A temperature transmitter is an electronic device that is used to convert the signal generated by the temperature sensor such as a thermocouple, RTD, or thermistor to the standard instrumentation signal. This signal indicates the temperature of the process under measurement and control. The most common instrumentation output signal in temperature transmitters is 4 to 20 mA or 0-10V DC ranges. For instance, 4mA can indicate 0°C and 20mA means 100°C. The temperature signal measured by the temperature transmitter is sent to the controller. The action required for the process, such as lowering or raising the temperature, is performed by relevant instrument ordered by the controller.