Air Pressure Gauge
Air pressure gauges are instruments specially designed to measure pneumatic pressure in a gas or liquid. They are used to measure and monitor the air pressure in any air-operated equipment. For instance, air pressure gauges can monitor air pressure in car and bike tires, airplane cabins, and scuba tanks, along with various machines used in manufacturing industries. Air pressure gauges are also sometimes connected to hand pumps.
Air pressure gauges typically use a Bourdon tube to measure pressures of 15 psi or more. Normal atmospheric pressure is 14.7 psi; Bourdon tubes are designed to measure pressure above normal atmospheric pressure. A Bourdon tube is a thin walled elastic tube of metal that is flat and formed into a C-shape, which flexes in response to an increase in pressure. When a pressure change occurs, the metal tube flexes, inciting movement of the gauge indicator.
The reading on an air pressure gauge can be displayed in many ways, including digital readouts, analog displays, and needles. There are also some air pressure gauges that have a display but monitor the pressure automatically. Air pressure gauges can be manufactured to turn on signal lights, sound alarms, or to operate components of machinery when the pressure changes.