Patent ID: 6527943
Filing Date: 2003-03-04
Classification: G01N,H01M,Y02E

Abstract:
A method of operating a sensor over a measuring range, said sensor measuring the concentration of an oxidizable species in a fluid mixture, said sensor comprising a solid polymer fuel cell in which said oxidizable species can be directly oxidized, a load across the terminals of said fuel cell, and an electrical meter for measuring an electrical output of said fuel cell, said fuel cell comprising an anode electrode directly supplied with said fluid mixture, a cathode electrode supplied with an oxidant at an oxidant stoichiometry, and a solid polymer electrolyte, wherein said fuel cell does not include a diffusion-limiting membrane operably linked to said anode electrode on the anode side opposite said solid polymer electrolyte, said method comprising:decreasing said load across said terminals of said fuel cell, wherein said decreased load is less than about 10 ohms; and increasing said oxidant stoichiometry, wherein said increased oxidant stoichiometry is greater than about 2, whereby saturation of said fuel cell electrical output is avoided over said measuring range.