Question

what is the difference between this two Pressure cited ?​

Answer 1

Explanation:

The difference between two pressures, p1 and p2, is known as the pressure differential, Δp = p1 - p2. In cases where the difference between two pressures itself represents the measured variable, one refers to the differential pressure, p1,2.

Answer 2

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There are two basic pressure types: absolute and gauge, distinguished by what pressure they are compared to, which is called the reference pressure. Gauge pressure's reference is ambient atmospheric pressure. Absolute pressure's reference is an absolute vacuum.