(1) Accurately measure the amount of air inhaled into the engine at all times.

(2) This is the main basis for ECU to calculate (control) the fuel injection quantity.

(3) Measure the air volume in the circulation path. Generally, the unit of instantaneous flow is cubic meters per hour, and the unit of cumulative flow is cubic meters.

Second, the installation location of the air flowmeter is as follows:

(1) between air cleaner and throttle body.

(2) It can be installed on the air filter.

(3) The air flow meter and throttle body can also be integrally installed on the engine.

Note: According to the different measuring principles, there are vane type, Carmen spiral type and thermal type air flow meters.

(1) The air flowmeter is an instrument that converts the inhaled air flow into an electrical signal.

(2) The advantage of the air flowmeter is that the pressure loss is extremely small and the measurable flow range is large. Generally, the ratio of the maximum flow rate to the minimum flow rate of air flowmeter is above 20: 1, and the applicable industrial pipe diameter is relatively wide, up to 3m. The output signal has a linear relationship with the measured flow, and the accuracy is high. It can measure the flow rate of acid, alkali, salt solution, water, sewage, corrosive liquid, mud, pulp and other fluids with conductivity ≥ 1μs/cm.

(3) But the air flowmeter can't measure the flow of gas, steam and pure water.

(See information: Baidu Encyclopedia: Air Flowmeter)