What is the function of an "orifice plate" in flow measurement?

The function of an orifice plate in flow measurement is to create a pressure drop across the plate, which allows for the calculation of flow rate. As fluid passes through the orifice, it accelerates, resulting in a reduction of pressure. This pressure drop can be measured and is directly related to the flow rate of the fluid through the pipe.

Using the principles of Bernoulli's equation and the continuity equation, the flow rate can be derived from the pressure differential measured before and after the orifice. This method is widely used in various industries due to its reliability and simplicity in flow measurement systems.

The other choices do not accurately describe the role of an orifice plate. An orifice plate does not block flow since it is designed to allow fluid to pass through while measuring the flow rate. It does not serve as a filter for contaminants or as a mixing device for multiple fluids, as these functions pertain to other types of equipment and processes.