What is the difference between an absolute pressure transmitter and a gauge pressure transmitter?

The concept of pressure type is involved in the selection of pressure transmitters: absolute pressure, gauge pressure, negative pressure and differential pressure.
Although their explanations are somewhat difficult to understand, the principle is actually very simple. The only thing you need to know is: the principle of these four pressure types is the principle of differential pressure, that is, one side is connected to the medium pressure, and the other side is the reference pressure. The difference is that the pressure connected to the reference pressure side is different.

For example, the absolute pressure transmitter measures the absolute pressure of the medium in the equipment, and its reference pressure is an absolute value of 0, which has nothing to do with atmospheric pressure, so there will be a vacuum sealed cavity on the low pressure side of the pressure core.

The gauge pressure transmitter measures the pressure based on atmospheric pressure. One side of the pressure transmitter is connected to the atmosphere, and the other side is connected to the measured pressure. Therefore, the reference pressure side is open to the atmosphere. For measuring liquid level in pipes and non-pressure tanks. If you pay close attention to the casing of some pressure transmitters, it is not difficult to find some small holes on it. These vent holes are reserved to keep the reference side connected to the atmosphere.

Differential pressure transmitters have two pressure tubes to measure differential pressure. If the differential pressure transmitter is only connected to the positive membrane chamber or the negative membrane chamber, its function is equivalent to that of a general gauge pressure transmitter. The pressure ports on both sides of the normal differential pressure transmitter will be connected to different pressures respectively. It is common to measure the liquid level of the sealed tank according to the pressure difference, and use the orifice plate to measure the flow of the pipeline and other applications.

Any interested in our pressure transmitter like UPB1 silicon pressure transmitter etc, please contact Stella Meng.