Patent ID: 7867371

Claim:
An electrochemical sensor, comprising: an elongated housing defining a longitudinal axis, the housing having a proximal end and a distal end configured to be exposed to a target fluid, the housing further defining a cavity substantially filled with a gelled or liquid reference electrolyte, the housing having an outer tubular wall formed of molded plastic, axially aligned with the longitudinal axis of the housing, the outer wall impermeable to the reference electrolyte and the target fluid, an inner tubular wall formed of molded plastic, disposed within the outer wall, and axially aligned with the longitudinal axis of the housing, the inner wall impermeable to the reference electrolyte and the target fluid, the inner wall defining an axial bore, and a cross member extending between the outer wall and the inner wall proximate the distal end of the housing, the cross member including a planar portion defining an aperture to enable electrochemical communication between the target fluid and the reference electrolyte within the cavity, wherein the cavity is bounded by the outer wall, the inner wall and the cross member; the cross member of the housing is formed of unitary construction of molded plastic with at least one of the inner tubular wall and the outer tubular wall a measuring electrode disposed in the axial bore of the inner wall and having an tip extending beyond the distal end of the housing to be exposed to a target fluid; a reference electrode disposed within the cavity of the housing, submerged in the reference electrolyte; and a junction plug comprising a porous material, the junction plug disposed in the distal end of the housing such that a distal surface of the plug is configured to contact the target fluid and a proximal surface of the junction plug is disposed adjacent to the cross member of the housing such that electrochemical communication between the target fluid and the reference electrolyte must pass through the aperture of the cross member.