Patent ID: 8815161
Filing Date: 2014-08-26
Classification: G01N,H01M,H05K,Y02E

Abstract:
1. A gas sensor for detecting a hydrogen concentration in an exhaust-gas pipe comprising: a first circuit board; a gas-sensing element case in which a gas-sensing chamber is formed, the gas-sensing element case having a first opening through which an exhaust gas to be monitored is allowed to enter the gas-sensing chamber and a second opening covered with the first circuit board; a sensor case secured to the exhaust gas pipe and including an installation hole, wherein the gas-sensing element case is fixed in the installation hole with an O-ring disposed on and between an inner side surface of the installation hole and an outer side surface of the gas sensing element case; a gas-sensing element mounted on the first circuit board and disposed in the gas-sensing chamber, wherein the first circuit board comprises a driving circuit configured to drive the gas-sensing element; a second circuit board installed in the installation hole opposite to the first circuit board and comprising a first control circuit configured to control the gas-sensing element via the driving circuit, wherein the second circuit board is disposed in a position outside the gas-sensing chamber and spaced apart from the first circuit board to have a space between the first circuit board and the second circuit board with a moisture-proof material being disposed over the first circuit board and in the space, a first temperature sensor provided in the gas-sensing chamber; a second temperature sensor provided on the second circuit board; and a heater provided in the gas-sensing chamber, wherein the second circuit board comprises a second control circuit to compare a first temperature from the first temperature sensor and a second temperature from the second temperature sensor to control the heater based upon comparison between the first and second temperature sensors.