Pressure Transducer: Definition, Principle, Types and Applications

What is a pressure transducer?

A pressure transducer, also known as a pressure transmitter, is a device that coverts pressure signal into an electrical signal. It generally consists of a sensing element. When subjected to pressure changes, the sensing element deforms, causing the corresponding electrical signal output to change. The pressure transducer is widely used to monitor and control the pressure in industrial processes, measure liquid level of storage tanks and ensure the normal operation of hydraulic and pneumatic systems. It plays a vital role in ensuring the safety, efficiency and accuracy of various systems and processes.

How does pressure transducer work?

Pressure transducer is a device that transmits pressure signals into standard electrical signals. It is usually used in industrial control systems. The principles mainly consist the following,

Piezoresistive pressure transmitter

The working principle of the piezoresitive pressure transducer is similar to pressure sensor. It converts pressure signal into resistance signal through piezoresistive effect. When external pressure is applied, the piezoresistive elements inside the sensor changes, causing the resistance value to change, and then outputs a corresponding voltage or current signal.

Capacitive pressure transmitter

Capacitive pressure transmitters use the capacitance effect to convert pressure signals. When external pressure is applied, the capacitance element inside the sensor changes, resulting in a change in capacitance value. By measuring the change in capacitance value, an electrical signal output proportional to the pressure can be obtained.

Flexible element pressure transmitter

Flexible element pressure transmitter uses the deformation of flexible elements (such as springs, diaphragms, etc.) to sense pressure signals. When external pressure is applied, the flexible element will deform, which will cause changes in parameters such as resistance, capacitance or inductance inside the sensor, and finally output the corresponding electrical signal.

Differences: pressure sensor, pressure transmitter and pressure transducer

Pressure sensor, pressure transmitter and pressure transducer are three common pressure measurement devices, their differences are as follows.

Pressure sensor

Pressure sensor is a sensor to measure pressure, it transmits pressure signals to electrical signals. Pressure sensor usually provides an electrical electrical signal output, usually a voltage signal or a current signal, which is used to indicate the magnitude of the measured pressure. Pressure sensors are commonly used in industrial control, automotive, medical and other fields.
Pressure transmitter
A pressure transmitter is a device that integrates a sensor and a signal processing circuit. It can convert the measured pressure signal into a standard electrical signal output, such as a 4-20mA signal or a 0-10V signal. Pressure transmitters usually have higher accuracy and stability and are suitable for industrial applications that require precise measurement.
Pressure transducer
A pressure transducer is a device that converts a pressure signal into another form of signal output, such as a voltage signal or a current signal. Pressure transducers are often used to convert pressure signals into other types of signals for communication or control with other devices or systems. 

In general, pressure sensors are the most basic pressure measurement devices, pressure transmitters have higher accuracy and stability, and pressure transducers can convert pressure signals into other types of signal outputs. When choosing which device to use, you need to consider the specific application requirements and measurement accuracy requirements.

Applications

Industrial automatic control system: Pressure transmitters are commonly used to monitor and control the pressure of liquids or gases in industrial processes, such as pressure monitoring and control in chemical plants, petrochemicals, pharmaceuticals and other industries.
Liquid level measurement: Pressure transducers are commonly used to monitor and control liquid or gas pressure in industrial processes. For example, pressure monitoring and controlling in chemical plants, petrochemical industries and pharmaceutical industries.
Pressure monitoring and alarm: Pressure transmitters can be used to monitor pressure changes in pipelines, containers or equipment. Once the pressure exceeds the set range, an alarm will be triggered to ensure safe operation of the equipment.
Air compressor control: The pressure transmitter can be used to control the operation of the air compressor, adjust the working state of the compressor according to the pressure signal, and maintain the stable operation of the system.
Automobile manufacturing: Pressure transmitters are often used in automobile manufacturing, such as engine oil pressure monitoring, brake system pressure monitoring, etc.
HVAC system：Pressure transmitters can be used to monitor and control gas or liquid pressure in HVAC systems to ensure proper system operation.

In general, pressure transmitters are widely used in the industrial field and can be used for pressure monitoring, control and alarm of various liquids or gases to ensure the safe operation of equipment and systems.