What tool is used to measure gas pressure in a system?

A manometer is the appropriate tool for measuring gas pressure in a system. It operates by comparing the pressure of the gas to a column of liquid, typically mercury or water. The manometer can provide precise measurements of pressure, especially in low-pressure applications commonly found in various gas systems. It’s particularly useful in HVAC installations, gas pipelines, and testing residential appliances to ensure they operate within safe and efficient pressure levels.

The other tools listed serve different purposes. A flow meter measures the flow rate of gases or liquids, providing information on quantity rather than pressure. A pressure gauge, while also used to measure pressure, typically indicates the pressure on a dial and is more commonly found in various industrial applications but may not provide the precision required for lower gas pressures compared to a manometer. An anemometer is designed to measure air velocity, which is unrelated to gas pressure measurements. Thus, in the context of measuring gas pressure accurately, a manometer is the correct tool.