Digital air pressure gauge instruments are widely used in various circumstances to measure the pressure of the gas medium with high precision, digital output, and easy reading advantages.The pressure sensitive elements are used to sense the pressures and PCBs are employed to transfer into and display the relative figures. Diaphram devices can be added to assist the pressure measurement of the special corrosive gas medium.
As a general rule a common plunge type gauge you would purchase will be accurate to + or – 3 psi when it is new. The accuracy of these type gauges are also affected by temperature, humidity and altitude. Note: Always check the tire pressure when the tires are cold, before traveling.
Pressure tubes function by taking the pressure and converting it into mechanical energy. This energy moves a dial in the gauge, displaying the current amount of pressure in the system. ... As pressure increases inside the tube, the force of the fluid attempts to straighten out the curved tube.
Air, oil and water pressure gages are interchangeable, as long as the pressure you are checking doesn't exceed the gage limit.
The difference is that water is an incompressible fluid — its density is almost constant as the pressure changes — while air is a compressible fluid — its density changes with pressure. Atmospheric pressure is the pressure exerted on a surface by the weight of the atmosphere (a compressible fluid) above it.