can be classified into several types, including differential pressure flow meters and pitot tube flow meters.
Differential pressure flow meters use a restriction in the pipe or duct to create a pressure drop, which is measured by two pressure sensors located upstream and downstream of the restriction. The difference in pressure between the two sensors is proportional to the flow rate.
Pitot tube flow meters use a device called a Pitot tube to measure air velocity directly. The Pitot tube consists of a small open-end tube that faces into the airflow, and a second tube that is perpendicular to the airflow and connected to a pressure sensor. As air flows past the open-end tube, it creates a static pressure, while the perpendicular tube measures dynamic pressure caused by air movement. The difference in pressures can be used to calculate air velocity and volumetric flow rate.
Both types of pressure-based air flow meters require calibration to ensure accurate measurement. Calibration involves comparing the meter’s readings with those from a reference standard at various known air flow rates and making adjustments as necessary.
