A compressor, as the heart of a refrigeration system, is a driven fluid machinery that elevates low-pressure gas to high-pressure gas. It sucks in low-temperature and low-pressure refrigerant gas from the suction pipe, drives the piston to compress it through the operation of the motor, and then discharges high-temperature and high-pressure refrigerant gas to the exhaust pipe, providing power for the refrigeration cycle. Thus achieving a refrigeration cycle of compression, condensation (heat release), expansion, and evaporation (heat absorption). Compressors are divided into piston compressors, screw compressors, centrifugal compressors, linear compressors, etc.

The actual responsibility of the compressor during work is to increase the pressure and elevate the suction pressure state to the discharge pressure state. Compression ratio is a technical representation of pressure difference, which means the absolute pressure on the high-pressure side divided by the absolute pressure on the low-pressure side. The calculation of compression ratio must use absolute pressure values. To avoid negative values in the compression ratio calculation, absolute pressure must be used instead of gauge pressure when calculating the pressure ratio. The use of absolute pressure values is necessary to make the calculated compression ratio positive and meaningful. Let's take a closer look at the application of pressure sensors in industrial air compressors.