Patent ID: 6083370
Filing Date: 2000-07-04
Classification: G01N

Abstract:
A gas sensor comprising:a main pumping means including an inner pumping electrode and an outer pumping electrode located inside and outside of a first chamber formed in a substrate comprised of solid electrolyte, for pumping-processing a first predetermined gas component contained in a measurement gas introduced from said external space into said first chamber, on the basis of a control voltage applied between said electrodes;an electric signal-generating conversion means including a detecting electrode and a reference electrode located inside and outside of a second chamber formed in said substrate, for generating, by conversion, an electric signal corresponding to an amount of a second predetermined gas component contained in said measurement gas after being pumping-processed by said main pumping means;a heater for heating at least said main pumping means and said electric signal-generating conversion means to a predetermined temperature;an impedance-detecting means for detecting an impedance between an electrode of said main pumping means and an electrode of said second chamber, said impedance detection means including an alternating current-generating circuit for supplying an alternating current between said electrodes subjected to said impedance detection; anda heater control means for controlling electric power application to said heater on the basis of a value of said impedance detected by said impedance-detecting means.