The instrument most commonly used to measure air pressure in ducts is called a?

The instrument most commonly used to measure air pressure in ducts is called a manometer. A manometer operates by measuring the height difference of a column of liquid, typically water or mercury, which is displaced by the air pressure within the duct. This displacement is then converted into a pressure measurement, allowing for effective assessment of duct system performance and airflow.

In the context of HVAC systems, ensuring proper air pressure in ducts is critical for maintaining efficiency and comfort in a building. By accurately measuring this pressure, technicians can identify issues such as leaks, blockages, or imbalances in the airflow, which are essential for effective HVAC operation.

Other instruments mentioned, such as a barometer and thermometer, serve different purposes. A barometer is designed to measure atmospheric pressure rather than the specific pressure within a duct, while a thermometer measures temperature rather than pressure. A monometer is not a commonly recognized instrument in HVAC terminology, further emphasizing that the correct term is manometer.