Air flow meter
An air flow meter is used for measuring intake air flow amount of an internal combustion engine. High performance engines require precise measurement of air/fuel ratio to achieve optimum performance and to meet current emission standards. This function is performed by an air flow meter. In an internal combustion engine, the intake air flow rate of the internal combustion engine is detected and used as a parameter for controlling the operation of the internal combustion engine. An internal combustion engine is equipped with an air flow meter for metering the amount of intake air supplied to the engine with a view toward attaining exhaust gas purification, economic fuel consumption and so on. The air flow meter is disposed in a bypass passage within an engine intake pipe. The air flow meter has a flow meter element and a heat sensing element, and measures the intake air flow mount base on a value of electric current supplied into the flow meter element. Generally known air flow meters which measure the intake air flow rate in an internal combustion engine of a car or the like include: an air flowmeter which measures the intake air flow rate according to heat radiation of a heating element to be controlled, and a thermal air flow meter which measures the flow rate according to the difference between the upstream and downstream temperatures of a heating element. The latter is called a temperature difference type thermal air flowmeter. Many current air flow meter sensors are based on the principle of a heated wire or film placed in or adjacent to the air flow. A hot wire air flow meter has a heating coil which is formed as an exothermic resistor that is disposed in an air flow path the flow rate of which is to be measured. The hot wire air flow meters are known as advantageous in comparison with the conventionally known flap type air flow meter because of lesser flow resistance against the flow of intake air flowing through an air induction passage.
Air flow meter product listings
ALIAVTX AVF7000 is a vortex flowmeters based on Von Karman theory of vortices generated by a bluff body in the pipe. The number of vortices are linearly proportional to the volumetric flow in the pipe.