Pressure Gauge Operating Principle
Most standard dial type pressure gauges use a bourdon tube-sensing element generally made of a copper alloy (brass) or stainless steel for measuring pressures 15 PSI and above. Bourdon tube gauges are widely used in all branches of industry to measure pressure and vacuum. The construction is simple yet rugged and operation does not require any additional power source. The C-shaped or spirally wound bourdon tube flexes when pressure is applied producing a rotational movement, which in turn causes the pointer to indicate the measured pressure. These gauges are generally suitable for all clean and non-clogging liquids and gaseous media. Low pressure gauges typically use an extremely sensitive and highly accurate capsule design for measuring gaseous media from as low as 15 INWC to 240 INWC (10 PSI). Digital gauges use an electronic pressure sensor to measure the pressure and then transmit it to a digital display readout.