Brief Introduction to the Working Principle of Air Flow Meter
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Air flow meter working principle is that under the condition of constant voltage of the air flow meter, the resistance of the air flow meter is changed by changing the intake air volume, thereby changing the current size and transmitting it to the car ECU. The air flow sensor, also known as the air flow meter, is one of the important sensors of the EFI engine. It converts the inhaled air flow into an electrical signal and sends it to the electronic control unit ECU, as one of the basic signals to determine the fuel injection, and is the sensor to measure the air flow inhaled by the engine. With the microcomputer used to control the fuel injection, several other types of air flow sensors have appeared, such as the valve-type air flow sensor and the Karman vortex air flow sensor.
The air flow meter is a device used to measure the amount of air entering the engine, and its working principle is somewhat similar to using thermal sensing to calculate flow rate. It places a heated metal wire or thermal film inside the intake pipe. When air flows past, it carries away heat, causing the temperature of the metal wire to drop. The ECU (the car's computer) monitors this temperature change—the greater the temperature drop, the higher the air flow rate. This allows the ECU to accurately calculate the intake air volume and then match the appropriate amount of fuel injection, ensuring the air-fuel mixture ratio is just right to improve combustion efficiency, making the car run smoothly and economically. If the air flow meter gets dirty or damaged, you may experience sluggish acceleration, rough idling, or even a spike in fuel consumption. Regular maintenance should include cleaning the air filter to reduce dust clogging. Nowadays, there are some new models on the market that use lasers or ultrasonic technology, but the hot-wire type remains popular due to its practicality and reliability.
