What device is used to indicate water pressure in pounds per square inch?

A pressure gauge is the correct device used to indicate water pressure in pounds per square inch (PSI). This gauge measures the force exerted by the water against a surface area, providing a direct reading of the pressure level within a system. Pressure gauges are commonly utilized in various applications, including fire apparatus and sprinkler systems, to ensure that the pressure is adequate for effective operation. They help in monitoring the performance of the system, ensuring safety, and preventing potential issues that could arise from incorrect pressure levels.

While a flow meter measures the rate of flow of liquids and gases, it does not provide information about pressure. A manometer typically measures pressure but is more specifically used for lower pressure applications or to measure pressure differences in certain contexts, often utilizing a column of liquid. A temperature gauge serves the purpose of measuring the temperature of a fluid and does not provide any information related to pressure. Therefore, the pressure gauge is the definitive tool for indicating water pressure in PSI.