The air vortex sensor uses whirlpools of air, or vortices, to measure the volume of air entering the engine. A triangular, vortex-generating rod disturbs the airflow and causes whirlpools of air to form in the body of the sensor.
The vortices alternate from clockwise to anticlockwise rotation, and they are staggered as they pass through a transmitter-receiver area. When there is no airflow, this transmitter emits a constant signal of ultrasonic waves to the receiver.
When the engine is running, the vortices distort the ultrasonic waves. This modulates the ultrasonic waves reaching the receiver. This modulated wave is converted to an electrical pulse signal which is directly proportional to the airflow. This is then used by the ECU to determine the basic fuel requirement.
An air regulator or rectifier is located at the entry to the sensor. It reduces turbulence in the airflow passing the vortex generator.
Source: CDX Global
