Which device measures the velocity of the air in a duct system?

Which device measures the velocity of the air in a duct system?

• A. An airflow station
• B. Anemometer
• C. Pitot tube
• D. Hygrometer

Answer: (A)

Measuring velocity in a duct system is best done with a device designed for duct measurements and balancing. An airflow station is built for this purpose: it’s installed in the duct and uses sensors (often including a differential pressure or pitot-based sensing) to directly determine velocity and usually flow rate, calibrated for the duct’s size and shape. This makes it the most practical and reliable single tool for getting accurate velocity readings in HVAC ductwork. An anemometer can measure air speed, but it’s typically a handheld spot measurement tool and not as well suited for integrated duct studies or balancing across multiple points. A Pitot tube measures velocity by converting dynamic pressure to speed, but it requires additional equipment and setup (manometers, calculations, and density data) and is usually used as a component within a larger measurement system rather than as a standalone duct-velocity instrument. A hygrometer measures humidity, which has no direct relation to air velocity.

Measuring velocity in a duct system is best done with a device designed for duct measurements and balancing. An airflow station is built for this purpose: it’s installed in the duct and uses sensors (often including a differential pressure or pitot-based sensing) to directly determine velocity and usually flow rate, calibrated for the duct’s size and shape. This makes it the most practical and reliable single tool for getting accurate velocity readings in HVAC ductwork.

An anemometer can measure air speed, but it’s typically a handheld spot measurement tool and not as well suited for integrated duct studies or balancing across multiple points. A Pitot tube measures velocity by converting dynamic pressure to speed, but it requires additional equipment and setup (manometers, calculations, and density data) and is usually used as a component within a larger measurement system rather than as a standalone duct-velocity instrument. A hygrometer measures humidity, which has no direct relation to air velocity.