Patent ID: 6666963
Filing Date: 2003-12-23
Classification: G01N

Abstract:
An electrochemical sensor for measuring atmospheric oxygen comprising:a housing having disposed therein a working electrode, a reference electrode and a counter electrode, and an electrolyte disposed in a reservoir therefore, the reservoir including an air space over the electrolyte, each of said working electrode, reference electrode and counter electrode comprising a catalytic material disposed on a surface of a porous support; a vent hole passing through the housing; the counter electrode being mounted within the housing to seal the vent hole with a porous support surface-facing the vent hole and a surface having catalytic material disposed thereon facing away from the vent hole; an electrolyte separator disposed between the electrolyte reservoir and the working and reference electrodes, the separator acting as a wall of the reservoir and preventing flow of electrolyte but permitting contact of electrolyte on both sides of the separator to maintain ionic conductivity; and a gas communicating means comprising a porous, hydrophobic solid material in contact with the catalytic material surface of the counter electrode and connecting the counter electrode to the air space in electrolyte reservoir, the gas communicating means permitting venting from the cell of air pressure which builds up in the reservoir, through the counter electrode.