What plumbing component is used to measure water flow?

In plumbing, a flow meter is specifically designed to measure the volume or flow rate of water in a system. It provides crucial information that can help in monitoring water usage and efficiency within plumbing systems. Flow meters work by detecting the velocity of water passing through a pipe and converting that measurement into a readable format, typically in gallons per minute (GPM) or liters per second (L/s).

This is particularly important for various applications like ensuring the appropriate flow for irrigation systems, domestic water supply, and in commercial setups where water needs to be carefully monitored. The other components listed do not serve this specific function: a pressure gauge measures the pressure within the system, a water level indicator shows the level of water in a tank, and an anemometer is used to measure air flow rather than water flow. Hence, the flow meter is the ideal choice for measuring water flow directly.