Patent ID: 7316767
Filing Date: 2008-01-08
Classification: G01N

Abstract:
1. A gas sensing element comprising: a heater including: a heater substrate; a heat generator provided on said heater substrate for generating heat when energized; and a heater terminal electrically connected through a heater lead to said heat generator; a spacer for a measured gas chamber into which a measured gas is introduced from the external; a spacer for a reference gas chamber into which a reference gas is introduced; a solid electrolyte plate including an electrochemical cell having a pair of electrodes for detecting a specified gas concentration on the basis of a minute current stemming from oxygen ions and flowing between said pair of electrodes, with said heater, said spacers and said solid electrolyte plate being built up into a multilayer construction, wherein a leakage current conducting path is provided in the middle of an electrical path between said heater and said electrochemical cell for leading a leakage current from said heater to a portion other than said electrochemical cell; and a pump cell comprising a pump cell solid electrolyte plate and a pair of pump electrodes provided on said pump cell solid electrolyte plate for pumping oxygen with respect to said measured gas chamber, and wherein said pump cell solid electrolyte plate includes pump leads electrically connected to said pair of pump electrodes and said pump leads are electrically connected to terminals exposed to the exterior of said gas sensing element, with said leakage current conducting path being made through the use of said pump leads.