Double junction reference electrode

A double junction reference electrode providing a precise and reproducible reference potential stable over at least a 24-hour time period,

• said electrode comprising
• a pair of in-line coaxial, vertically-oriented sealable, tubular fluid compartments including an upper compartment and a lower compartment each adapted to retain an electrically conductive chemical composition therein,
• joinder means coaxial with said upper compartment and with said lower compartment and interposed therebetween for mechanically and dissociably intercoupling said compartments in fluid-tight interengagement with one another,
• fluid-retentive, fluid-flow-restricting first conduit means supported by and extending axially through said joinder means for providing an ion-permeable electrically conductive fluid path between said upper compartment and said lower compartment,
• cap means surmounting said upper compartment for sealing an upper open end thereof, to provide a fluid-tight closure therefor,
• electrically conductive external cable means sealed into to extend through said cap means in electrically conductive communication with said upper compartment interiorly thereof,
• plug means sealing a lower open end of said lower compartment as a fluid tight closure therefor,
• fluid permeable second conduit means extending axially through said plug means for providing an electrically conductive fluid-permeable junction between said lower compartment and a test system exterior of said electrode.