Ion-responsive electrode construction

Claim 1

In an electrode for use in measuring the activity or concentration of a predetermined ion in a test solution, said electrode being of the type including a container holding an electrolyte solution and having at one wall portion thereof a thin ion-sensitive membrane exposed at its inner surface to said electrolyte and adapted to be exposed at its outer surface to the test solution for the purpose of developing an electrical potential responsive to the activity or concentration of the predetermined ion; that improvement in the foregoing type of electrode which comprises: a rigid member of porous inert material serving as part of said wall portion of said container and arranged for exposure at one surface thereof to said electrolyte, said rigid member having a higher melting temperature than said ion-sensitive membrane; said rigid member carrying on a surface thereof opposite said one surface said thin ion-sensitive membrane in the form of a separate member fused to said rigid member with the ionsensitive membrane material interengaged with pores of the rigid member to effect a tight-locking seal engagement between said two members; the porosity of said inert material providing continuous channels through which said electrolyte can travel to contact the material of said membrane in pores at the interface between said two members; the opposite surface of said membrane being arranged for exposure to said test solution; said porous material being substantially thicker and mechanically stronger than said membrane.