Measuring differential pressure is very widely used in measurement and control engineering. Often the differential pressure measurement
is then an indication of something else. The most common applications is filter monitoring, where the measured differential pressure
across a filter gives an indication of how dirty that filter is. A differential pressure measurement combined with a pitot tube or
measuring flange gives an indication of flow, and by measuring the differential pressure between the top and bottom of a tank, you know
what the level is in the tank. Furthermore, differential pressure gauges are widely used to measure differential pressure between two
spaces. A differential pressure measurement can thus also be applied as under- or overpressure monitoring.