Air Compressor Gauges

Most pressure gauges work on a Bourdon Tube principle. This is an oval hollow tube bend just short of a full circle. When pressure is put inside this tube, the tube tries to straighten itself. While moving it pulls a needle and the needle shows the reading of the pressure or the vacuum. When you select a pressure gauge, the diameter of the gauge will be determined by the distance from where you want to take a reading, but the most important is your normal working pressure.

Airpower always tries to have the normal working pressure, as close as possible to the middle of the scale. The gauge is the most accurate in the middle and the gauge will indicate if the pressure is too low or too high. Pressure gauges measure the difference between the pressure in the line and the atmospheric pressure. This is why it is called gauge pressure. If you want the absolute pressure, you must add the atmospheric pressure to the gauge pressure reading. Gauges are instruments and if not handled with care, you will not get an accurate reading.