Patent ID: 8110081

Claim:
A galvanic fuel cell oxygen sensor comprising: (a) an inner core housing containing an electrolyte, a cathode electrode, an anode electrode enclosed in a porous membrane permeable to oxygen; (b) an outer housing for containing the inner core housing and having a cap at one end of the outer housing, where the cap has a sample inlet port and a sample outlet port arranged such that a gas drawn in through the sample inlet port is exposed to the cathode electrode and the porous membrane before exiting the sample outlet port; and (c) said inner core housing being hermetically sealed within the outer housing except for the presence of said sample inlet port and same outlet port in the cap and a pressure equalization port extending into the inner core housing and out through a sealed opening in the outer housing; (d) a printed circuit board located at an end of the inner core housing opposite from said one end, said printed circuit board having conductive connections to the cathode electrode and the anode electrode and with the pressure equalization port extending through an aperture in the printed circuit board; (e) a gas impervious potting compound covering a predetermined surface of the printed circuit board and filling a void between the printed circuit board and the outer housing without occluding the equalization port; and (f) means for maintaining substantially equal pressures on opposite sides of said membrane.