Instrument for measuring the condition of a fluid (liquid or gas) that is specified by the force the fluid would apply, when at rest, to a unit area, such as pounds per square inch (psi) or pascals (Pa). The reading on the gauge, called the gauge pressure, is always the difference between two pressures. When the lower of the pressures is that of the atmosphere, the total (or absolute) pressure is the sum of the gauge and atmospheric pressures
A water level gauge that is operated by the change in pressure at the bottom of a body of water due to the rise and fall of the water level See gas purged pressure gauge
A gauge with an analog dial indicating the pounds per square inch (psi) of pressure that has built up within a closed container, such as a filter
round dial located on backwash valve or on top of filter Indicates in pounds per square inch the pressure in the filter When the pressure reads 10 psi or more above what it did wen the filter was freshly clean, the filter needs to be cleaned