What device is used to measure the flow rate of liquids?

The flow meter is the device specifically designed to measure the flow rate of liquids. It works by quantifying the amount of liquid that passes through a specific point in a given period of time. This measurement is critical in various applications, such as water supply systems, chemical processing, and HVAC, where understanding the flow rate helps in monitoring, controlling, and optimizing processes.

Flow meters can vary in design and function, with some types employing mechanical principles while others may use electromagnetic or ultrasonic techniques to achieve accurate measurements. The precise data provided by flow meters ensure that systems operate efficiently and safely.

In contrast, the other devices listed serve different purposes. A pressure gauge measures the pressure within a system, providing important information about the force exerted by the fluid, but it does not give flow rate data. A level sensor detects the height of a liquid within a container, which can be useful for ensuring adequate supply but does not measure flow. A thermometer measures temperature, which is unrelated to flow rates altogether. Therefore, the flow meter is uniquely suited for measuring how much liquid is moving through a system over time.