Differential pressure is the pressure difference between two independent measuring points. True differential pressure can be measured using a single diaphragm sensor with two independent pressure connection ports – exposing the diaphragm to different pressure media on each side of the diaphragm. The measurement will provide the pressure difference between the two sides of the diaphragm.

Alternatively, differential pressure can be determined using two absolute pressure sensors by mathematically calculating the difference between the two independent measuring points.

Differential pressure can be used to measure flow conductance over gas or air filters as the differential pressure increases if contamination builds up in the filter.

Differential pressure applications

Differential pressure is also a critical parameter to measure and control in clean rooms, where the atmosphere is controlled. In clean room environments used in the semiconductor industry, the ambient room pressure is elevated to maintain a positive pressure, thereby preventing inrush of particulates.