Air flow meter is an instrument used to measure linear, nonlinear, mass or volumetric flow rate of air or gas. Air-Flow sensors are used for measurement of air flow in airflow meters. Bidirectional air flow sensors can detect the air flow in both the directions. Air flow sensors are suitable for large gas and air flows, such as respiration and wind. The high accuracy makes it capable to detect very low gas flow velocities.

The Air flow sensor contains a silicon sensor chip, a special actuation circuit, an amplification circuit and a signal conditioning circuit. The sensor chip is actuated to heat up the air locally. The movement of the heated air is detected by the sensor in both directions. This principle makes the sensor very sensitive. Therefore the amplification could be held at a low value. The signal conditioning circuit keeps the sensitivity to a constant level at different temperatures.

The air flow sensor is designed to detect air flow in the free field. There is no physical connection to the flow conductor and the sensor just captures bypassing gas flow.

Air flow meter is commonly abbreviated as AFM and also known as air consumption meter. This is a device that can measure how much air flows through a tube. It would be a mistake to conclude that air flow metes measure the volume of air passing through a tube. The actual function of an air flow meter is to calculate the speed in which air passes through the tube in a particular time segment. This device has found usage in various modern machines where calculating the amount of gas passing through a particular pipe is important in order to monitor the performance of the device.

Typical Applications of Airflow Sensors:

* Bi-directional air flow sensing
* Breathing measurement
* Control of building flows
* Natural gas flow monitoring
* Process control