The device that can detect the pressure value and provide a remote signal is collectively referred to as the pressure transmitter, which is a sensor commonly used in industrial automation process control to measure the pressure of a gas or liquid, and convert this pressure value into a measurable and transferable electrical signal.
These electrical signals are typically standard current or voltage signals, such as 4-20mA current signals or 0-10V/0-5V voltage signals, to facilitate remote transmission, display, recording or control in industrial automation, process control, monitoring and measurement systems.
It can meet the requirements of centralized detection and control of automation system, and is widely used in industrial production.
Composition of pressure transmitter:
The pressure transmitter usually consists of a pressure sensitive element (such as a strain gauge, capacitor diaphragm, piezoresistive chip, etc.) and a signal processing circuit.
When the measured medium acts on the pressure sensitive element, it will cause some physical change in the element (such as resistance change, capacitance change, resonant frequency change, etc.), which is then converted into an electrical signal.
The signal processing circuit is responsible for amplifying, linearizing, and temperature compensating this electrical signal to output a stable and accurate pressure value.
Types of pressure transmitters
The structure of the pressure transmitter is varied, according to the working principle, there are strain type, piezoresistive type, capacitance type, piezoelectric type, vibration frequency type and so on. The following is a brief introduction to several commonly used pressure transmitters.
The strain gauge pressure transmitter has a large measuring range, the measured pressure can reach hundreds of mpa, and has good dynamic performance, suitable for rapidly changing pressure measurement.
But there are more obvious temperature drift and time drift, this instrument is more used in the general requirements of dynamic pressure detection; Piezoresistive pressure transmitter is manufactured according to the piezoresistive effect principle, and its pressure sensitive element is the diffusion resistance made of integrated circuit technology on the substrate of semiconductor material. When it is subjected to external force, the resistance value of the diffusion resistance changes due to the change of resistivity.
Strain gauge pressure transmitter
