The selection of the transmitter is usually considered according to the installation conditions, environmental conditions, instrument performance, economy and application medium. In actual use, it is divided into direct measurement and indirect measurement; its uses include process measurement, process control and device interlocking. Common transmitters include ordinary pressure transmitters, differential pressure transmitters, single flange transmitters, double flange transmitters, plug-in flange transmitters, etc.


  • 1. What is a transmitter
  • 2. The working principle of the transmitter
  • 3. Transmitter wiring diagram
  • 4. The role of the transmitter

1. What is a transmitter

The transmitter (transmitter) is an important part of the automatic control system. It plays a pivotal role in the field of instrumentation and industrial automation. The transmitter measures temperature, pressure, liquid level, composition and other physical quantities and converts them into a unified In addition to the standard signal, it also has a certain amplification effect.

When the signal converter is integrated with the sensor, it becomes a transmitter. According to the definition of “Encyclopedia of China”, a transmitter is a sensor whose output is a standard signal. The national standard is defined as a device that outputs a prescribed standard signal as a transmitter.


2. The working principle of the transmitter

In general, the working principle of the transmitter is that the transmitter sends a signal to the secondary instrument to display the measurement data. A device that converts physical measurement signals or ordinary electrical signals into standard electrical signal output or can be output by means of communication protocols. Generally divided into: temperature/humidity transmitter, pressure transmitter, differential pressure transmitter, liquid level transmitter, current transmitter, power transmitter, flow transmitter, weight transmitter, etc. Transmitter follows a physical law (or experimental mathematical model) to convert changes in physical quantities into standard signals such as 4-20mA. The transmitter is a converter that converts the output signal of the sensor into a signal that can be recognized by the controller. It can also convert the non-electricity input from the sensor into an electrical signal while amplifying it for remote measurement and control.


3. Transmitter wiring diagram

The wiring diagram of the transmitter is as follows:


4. The role of the transmitter

There are many types of transmitters. According to the working energy, there are pneumatic transmitters and electric transmitters; according to the measured parameters, there are differential pressure, pressure, flow, temperature, liquid level and other transmitters.
Transmitters play a pivotal role in the fields of instruments, meters and industrial automation. Unlike sensors, transmitters generally have a certain amplification effect in addition to converting non-electricity into measurable electricity.