| 摘要 |
<p>PURPOSE:To provide the measuring apparatus, of the air-fuel ratio of a purge gas, which can deal with even an air-fuel ratio region in a wide range and which can surely deal with the feedback control of a purge. CONSTITUTION:Specific infrared light (intensity: I0) is made incident into a chamber 3 from a transparent glass window part 6 for incidence, the light which has entered the chamber 3 is first made incident on a transparent glass window part 7, the light is reflected, and its reflected light is reflected by a transparent glass window part and reflected additionally by a transparent glass window part 8 in such a way that the light is made incident, collided and reflected sequentially. Then, for example, according to an air-fuel ratio based on the intensity of transmitted light detected by sensors 12, 13, the sensors 12, 13 for air-fuel-ratio measurement are selected. That is to say, when the air-fuel ratio is rich, the sensor 12 whose transmission distance L (=L1) is short is selected, and, when the air-fuel ratio is lean, the sensor 13 whose transmission distance L (=2L1) is selected. The air-fuel ratio based on the intensity of the transmitted light detected by the selected sensor 12 or 13 is output as a measured value.</p> |
