1. transmitter is a signal source converter, which converts the output signal of the sensor into a signal that can be recognized by the controller or converts the non-electric quantity input by the sensor into an electric signal and amplifies it at the same time for remote measurement and control. As the name implies, transmitter means "change" and "send". The so-called "change" refers to the transformation of various physical quantities from sensors into electrical signals.
2. The so-called "sending" refers to all kinds of electrical signals. In order to facilitate the receiving and sending of other instruments or control devices, the electrical signals from sensors are unified again through electronic circuits. This "change"+"send" constitutes the most commonly used transmitter in modern times.
3. There are many kinds of transmitters, such as temperature transmitter, pressure transmitter, flow transmitter, current transducer, voltage transmitter, etc.