Why is a pressure drop used in measuring flow through an orifice plate?

A pressure drop across an orifice plate is a critical measurement for determining flow rate. When fluid flows through an orifice, the cross-sectional area decreases, which causes the velocity of the fluid to increase and the pressure to drop. This relationship between the pressure drop (also known as differential pressure) and the flow rate is described by Bernoulli's principle and can be quantified using equations derived from fluid dynamics, such as the orifice flow equation.

By accurately measuring the pressure drop, technicians can calculate the flow rate of the fluid passing through the orifice. This technique is widely used in various applications, such as in pipelines and process control systems, to monitor and manage fluid flows effectively. Understanding the correlation between pressure drop and flow rate is essential for optimizing operations in industrial settings.