| Air flowmeter is a kind of important instrument for measuring air flow rate. It derived from the beginning of 20 centuries and is widely used to measure the speed of wind. Besides, it has been one of the key techniques in the field of measuring velocity of flow since 1960's. In recently years, in the development of microelectronic and micro-machining technique, the power consumption of hot-wire(film) resistance adoption of micro-structure reduced greatly. For the more, because of the faster thermal response time, it takes into account again. The development of autoelectronics brings out more wide application for the hot-wire(film) air flow sensor. In the way of measuring air flow rate of the engine, the hot-wire(film) air flow sensor is widely used as a result of reacting mass of air directly and no density compensation. Accordingly, it is extensively used to the engine of the car.According to the measurement principle of constant temperature way, this paper designs a kind of hot-wire(film) air flow sensor with low-cost and rapid thermal response time. This paper demarcates the air flow sensor in the labeled test-bed and studies the way of modeling for the nonlinear static characteristic curve. All of the work establish the foundation for the ECU(Electronic Control Unit) computing the volume dose of the gas and actual practice. This paper uses analytic modeling method and numerical modeling method to identify the precision of the air flow sensor. The results show that only one of the five modeling based on mechanism of sensor has higher precision, the polynomial model based on least square method is the same as that based on functional link neural network, demand of measurement can be satisfied with the models. BP neural network has higher precision of identification but it is a model without concrete parameters. It can be used to emulation computation of theoretic mixture ratio control system in the engine.
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