| 摘要 |
<P>PROBLEM TO BE SOLVED: To precisely control an impression voltage, and to enhance detection precision of a gas concentration over a wide range, in a gas concentration detector. <P>SOLUTION: A sensor element 10 of an A/F sensor has a gas diffusion rate determining part, a solid electrolyte and a pair of electrodes, and an element current flows in response to the concentration of a specified component in each time in accompaniment with voltage impression to the sensor element 10. An impression voltage control circuit 30 controls the impression voltage to the sensor element 10, based on an impression voltage characteristic specified linearly. The impression voltage characteristic is set therein within a wide air-fuel ratio detecting range, based on a width of a limiting current area at each air-fuel ratio. <P>COPYRIGHT: (C)2004,JPO&NCIPI |
