What are the methods to check the pressure gauge?

After removing or replacing parts, the pressure gauge needs to be calibrated before it can be used. There are three calibration methods: pump pressure calibration, air pressure calibration and pressure calibrator calibration. It can be selected according to the nature of the pressure gauge and different pressure values. Pressure gauges with a pressure value of 0 ~ 0~ 1.47MPa can generally be tested by air pressure; For pressure gauges above 34.3kPa, the pump pressure calibration method can be used; Pressure gauges with large pressure values are generally calibrated by calibrators. In actual maintenance, air pressure calibration and pump pressure calibration are commonly used.