What is the difference between 4~20mA pressure transmitter and pressure gauge?

- Jul 18, 2019-

What is a 4-20mA pressure transmitter?

The pressure transmitter is mainly composed of a sensing element (also called a pressure sensor), a measuring circuit and a process connection. It can convert the physical pressure parameters such as gas and liquid felt by the pressure sensor into standard electrical signals (such as 4-20 mA DC, etc.) to supply secondary instruments such as alarms, recorders, and regulators for measurement, instructions and process adjustments.

What is a pressure gauge?

A pressure gauge is a meter that uses a spring element as a sensitive component to measure and indicate the pressure that is above ambient pressure. The application of pressure gauges is extremely common and it covers almost all industrial processes and scientific research fields. In the field of heat pipe network, oil and gas transmission, water supply and gas supply system, vehicle maintenance and repair shop, etc. can be seen everywhere. Especially in the process of industrial process control and technical measurement, mechanical pressure gauges are more and more widely used due to the high mechanical strength and convenient production of elastic sensitive components of mechanical pressure gauges.

What is the difference between pressure transmitters and pressure gauges?

1. The accuracy of the standard instrument required for pressure transmitter calibration is much higher than the standard instrument accuracy required for pressure gauges.

2. The pressure gauge only needs to verify the relationship between input and output, while the pressure transmitter may need to verify the relationship between the input and the communication data.

3. The accuracy of the pressure gauge is poor, there is no output, and it is not possible to use the hand-operator. Generally, 5 points are checked, and the difference between the back and forth is different. Intelligent pressure transmitters generally only need to check the zero point and full scale.

4. The pressure gauge output is the scale indication. The pressure transmitter is the current output and must be connected to an ammeter display of the appropriate accuracy level.

The above description is not difficult to see that under the same working conditions, the pressure value measured by the 4-20 mA pressure transmitter is more accurate, and the later function expansion is much higher than the pressure gauge.