Patent ID: 7972495

Claim:
A method for manufacturing a pH probe, the method comprising: providing a probe housing comprising an inner tube concentrically arranged within an outer tube of the probe housing; forming one or more diffusion windows within a sidewall of the outer tube proximate to a first end of the outer tube; arranging a plurality of electrodes each having a sensing portion and a conductive portion within the probe housing, wherein said arranging ensures that a sensing portion of one of the plurality of electrodes protrudes from a first end of the probe housing and a conductive portion of each of the plurality of electrodes protrudes from a second end of the probe housing, wherein at least one of the plurality of electrodes comprises a pH-sensitive electrode having a sensing portion with a smooth hemispherical tip formed by dipping one end of an antimony rod fragment into a molten antimony solution and allowing the sensing portion to harden while pointing in a downward direction; sealing the first and second ends of the probe housing with a sealant material, such that the protruding portions of the plurality of electrodes remain exposed; and inserting an electrolytic solution into a space bounded by the outer tube, the inner tube and the sealant material, wherein said inserting comprises filling an entirety of the space with the electrolytic solution during manufacturing of the probe.