What is the difference between vacuum pressure gauge and pressure vacuum gauge?

In fact, the empty gauge is a kind of pressure gauge.
The vacuum pressure gauge du is based on atmospheric pressure and is used to measure the force less than atmospheric pressure.
Pressure vacuum gauges are based on atmospheric pressurePressure gauge back flange and are used to measure gauges greater than and less than atmospheric pressure.

Pressure vacuum gauges are widely used in gas transportation, measuring the pressure of various liquids, gases, steam and other media that are non-corrosive, non-explosive, non-crystalline, and non-solidified in pipeline liquids and airtight containers. It has the advantages of simple structure, high cost performance, intuitive instructions, reliable performance, etc.