An instrument to be inserted into a duct for measuring velocity pressure is the?

An instrument to be inserted into a duct for measuring velocity pressure is the?

• A. Pitot tube
• B. Manometer
• C. Thermistor
• D. Thermometer

Answer: (A)

Measuring velocity pressure in a duct relies on capturing the dynamic pressure created by moving air. A Pitot tube is designed to be inserted into the duct with its opening facing the flow to measure stagnation (total) pressure. By also measuring static pressure from a separate port, you can obtain velocity pressure as the difference between stagnation and static pressures. This dynamic pressure is related to velocity through pv = 1/2 rho v^2, so knowing pv lets you calculate airspeed. A manometer reads pressure differences but isn’t by itself a velocity sensor, while thermistors and thermometers measure temperature, not pressure. So the Pitot tube is the instrument that provides velocity pressure measurement inside a duct.

Measuring velocity pressure in a duct relies on capturing the dynamic pressure created by moving air. A Pitot tube is designed to be inserted into the duct with its opening facing the flow to measure stagnation (total) pressure. By also measuring static pressure from a separate port, you can obtain velocity pressure as the difference between stagnation and static pressures. This dynamic pressure is related to velocity through pv = 1/2 rho v^2, so knowing pv lets you calculate airspeed. A manometer reads pressure differences but isn’t by itself a velocity sensor, while thermistors and thermometers measure temperature, not pressure. So the Pitot tube is the instrument that provides velocity pressure measurement inside a duct.