Wondering how pressure differential switch works! let's see

A pressure differential switch is designed to sense a difference in pressure between two pressure sources for control purposes.

The pressure ports for high process pressure and low process pressure are separated by an elastic diaphragm. The difference in pressure that exist between the two ports causes axial movement of the diaphragm against the measuring range spring. This axial movement is used to actuate the contacts of a micro-switch depending on the setpoint of the differential pressure switch.