What instrument is used to measure air flow pressures?

The instrument that is correctly associated with measuring air flow pressures is the Pitot tube. This device is specifically designed to measure the dynamic pressure of fluid flow, which in the context of air, means it evaluates the velocity and pressure of the airflow in ducts or around structures. The Pitot tube operates based on the principles of Bernoulli's equation, where it captures pressure differences to calculate the speed of the airflow and is widely used in aerodynamics and HVAC applications.

The manometer, while it does measure pressure, is typically used for static pressures rather than airflow dynamics. It measures the pressure of gases or liquids relative to a vacuum or another liquid level but does not directly assess air flow in the same context as a Pitot tube.

The barometer is primarily used to measure atmospheric pressure; it does not measure airflow or airspeed directly.

An altimeter measures altitude by comparing the atmospheric pressure at a given location with a standard atmospheric pressure. While it relates to pressure, it is not designed for measuring airflow pressures.

Thus, the Pitot tube stands out due to its specific functionality in the context of airflow measurements.