Orifice plates, venturi tubes, and nozzles belong to which group?

Orifice plates, venturi tubes, and nozzles are devices used to measure the flow rate of fluids, primarily by creating a differential pressure that correlates to the flow velocity. This group of devices is classified as head meters because they operate on the principle of fluid dynamics, where the flow rate is determined by measuring the pressure drop across the device. The head created (or the drop in pressure) is directly related to the flow rate through the application of principles from Bernoulli's equation.

In these devices, the change in elevation or pressure can be expressed as "head," which is crucial when calculating how much fluid is flowing through the system. The measurements taken can then be used to derive the flow rate based on specific fluid characteristics and the physical properties of the devices themselves. This accurate measurement of flow is essential in many applications such as water treatment, chemical processes, and HVAC systems, making them vital tools in the field of power engineering.

The other choices refer to different functions within engineering systems. Flow sensors directly measure flow but do so through various technologies and mechanisms that may differ from the head meters’ differential pressure method. Pressure regulators control and maintain pressure in a system, while temperature controls monitor and manage temperature levels but do not pertain