ALCOHOL CONCENTRATION SENSOR AND ALCOHOL CONCENTRATION MEASURING INSTRUMENT

摘要

PROBLEM TO BE SOLVED: To provide an alcohol concentration sensor for precisely measuring the concentration of an alcohol within an alcohol concentration range having a relatively low concentration to control a precise air/fuel ratio in an internal combustion engine using alcohol mixed gasoline. SOLUTION: The alcohol concentration sensor is constituted of an insulating substrate 2 and the a pair of the thin film electrodes 4 and 5 arranged on the surface of the insulating substrate 2 so as to form an electrostatic capacity. A material with a relative dielectric constant of 5 or below is used as the insulating substrate 2 and the thin film electrodes 4 and 5 are covered with an insulating protective film. A material with a relative dielectric constant of 5 or below is used as the insulating protective film. The alcohol concentration sensor is equipped with a pair of the extraction electrode 10 and 11 respectively connected to the thin film electrodes 4 and 5 and further equipped with a resin mold 12 for sealing the connection end parts of the thin film electrodes 4 and 5 of the extraction electrodes 10 and 11 with the thin film electrodes 4 and 5 and a part of the insulating substrate 2. The resin mold 12 is formed so as to expose the surface having the thin film electrodes formed thereon of the insulating substrate 2. COPYRIGHT: (C)2005,JPO&NCIPI