A transmitter is a converter that converts an output signal of a sensor into a signal that can be recognized by a controller (or a signal source that converts the non-electrical quantity of the sensor input into an electrical signal while amplifying it for remote measurement and control). The sensor and the transmitter together form an automatically controlled monitoring source. Different physical quantities require different sensors and corresponding transmitters. Many types of transmitters, used in the industrial instrument above the transmitter mainly temperature transmitter, pressure transmitter, flow transmitter, current transducer, voltage transmitter and so on.