| 摘要 |
An air flow measuring circuit is provided to measure the air flow rate of exhaust gas by being applied on an exhaust gas device of a diesel automobile and to maintain stable property in a vehicle having high vibration. An air flow measuring circuit comprises a power source, a variable resistor, an air flow rate sensor(130), a current-flux calculator, and a thermocouple. The variable resistor is connected to one side of the power source. The air flow rate sensor is connected between the variable resistor and the power source. According to the air flow rate, the air flow rate sensor senses the resistor variation of the platinum evaporated on an alumina substrate(131). The current-flux calculator is parallely connected to the air flow rate sensor. According to the resistor variation and temperature, the current-flux calculator calculates the air flow rate. The thermocouple is connected to the current-flux calculator and measures the temperature. |
