pressurechange

Pressure change is any variation in the pressure exerted by a fluid or gas on its surroundings. Pressure can be absolute, gauge, or differential. Absolute pressure is relative to a vacuum; gauge pressure is relative to ambient atmospheric pressure; differential pressure is the difference between two pressures. Common units are pascals, kilopascals, bars, and pounds per square inch.

Changes in pressure arise from changes in volume, temperature, or flow conditions. In gases, compression increases pressure, while expansion lowers it (ideal gas law). In moving fluids, velocity changes can cause pressure changes (Bernoulli's principle). Dynamic or transient changes include shocks, surges, and pulsations.

Measuring pressure changes uses devices such as barometers, manometers, and electronic sensors (piezoelectric, capacitive). Analysts track P over time, including dP/dt, to assess system behavior. Differential and relative measurements are common for devices like filters, pumps, and pipelines.

In meteorology, pressure changes drive weather systems and winds. In aviation, pressure data underpin altitude measurement. In engineering, monitoring pressure change helps detect leaks, blockages, or valve faults. Physiological contexts monitor blood pressure and intracranial pressure to assess health and safety.

Examples include a drop in atmospheric pressure signaling an approaching storm, rapid tire deflation rate showing a puncture, and water hammer from sudden valve closure causing a pressure spike in pipes.