Capillary reference half-cell

A combination electrode, comprising:

• (a) a capillary having a length further having a portion of an amount of reference solution liquid therewithin;
• (b) said capillary constraining said portion of said reference solution liquid from free flow volume discharge and said capillary having a first and second end, said first end further having a closure, said second end open, thereby forming at least one liquid junction between said reference solution liquid and said test solution liquid, and permitting diffusion between said reference solution liquid and said test solution liquid;
• (c) an electrode element placed in contact with said reference solution liquid nearer said first end than to said second end wherein a voltage potential is related to a chemical concentration of said reference solution liquid, said voltage potential is constant while diffusion occurs until the diffusion dilutes said reference solution liquid near said electrode element so that time in service depends upon the length of the capillary;
• and
• (d) a sensing electrode mounted exterior to said capillary and in contact with said test solution liquid, thereby forming a sensing half-cell.

A method of using a capillary reference half-cell, comprising the steps of:

• (a) filling a capillary with a portion of a reference solution liquid, said capillary having a first and second end, said first end closed, said second end open,
• (b) placing an electrode nearer said first end than to said second end and in contact with said reference solution liquid,
• (c) inserting said second end into a test solution liquid together with a second sensing half-cell for obtaining electrochemical measurements, and
• (d) preventing free flow volume discharge of said reference solution liquid into said test solution liquid.