Patent ID: 6290829
Filing Date: 2001-09-18
Classification: G01N

Abstract:
A gas sensor comprising:a main pumping means for pumping-processing oxygen contained in a measurement gas introduced from an external space into a processing space formed and comparted by solid electrolytes contacting with said external space;a main pumping control means for comparing a partial pressure of oxygen in said processing space with a first reference value to control said main pumping means so that said partial pressure of oxygen has a predetermined value; andan electric signal-generating conversion means for decomposing a measurement gas component contained in said measurement gas after being pumping-processed by said main pumping means, by the aid of a catalytic action and/or electrolysis for creating an electric signal corresponding to an amount of oxygen produced by said decomposition wherein:a measurement gas component contained in said measurement gas is measured on the basis of said electric signal supplied from said electric signal-generating conversion means, said gas sensor further comprising:an oxygen concentration-detecting means for detecting a concentration of oxygen contained in said measurement gas after being pumping-processed by said main pumping means;a correcting control means for correcting and controlling said main pumping control means on the basis of a difference between a detected value supplied from said oxygen concentration-detecting means and a second reference value to give a constant concentration of oxygen contained in said measurement gas after being pumping-processed by said main pumping means; anda self-diagnosis means for comparing said detected value supplied from said oxygen concentration-detecting means with a prescribed range to decide whether or not any abnormal condition occurs, on the basis of a result of said comparison.