A differential pressure gauge measures the difference in pressure between two connections.
As a result, let’s imagine an application where you have a tank at 100 psi and another at 95 psi.
If you connect a differential pressure gauge between those two tanks, you will read 5 psi.
Differential Pressure Gauge
There are a few different gauge designs to achieve this, but Differential Pressure Plus manufacturers a design known as a “Magnetic Coupling.” Each gauge has a magnetic piston that moves back and forth like a sea-saw depending on the differential pressure.
As a result, the linear movement of this magnetic piston pushes and pulls on a rotary magnet that connects to the pointer. This “magnetic rack and pinion” provide the readout.