This method was patented by Valeria Rácz and Endre Simonyi at 1968. The electrical conductivity of week acid or base is a little value but salt of a week acid and a week base is a high value therefore it can measure of the concentration of a week acid or base if we react the week acid with a week base and vica versa.
The conductivity of the product is a linear function of the concentration of the measuring material.
The surplus of the reagent is not disturb because the value of the conductivity is a little value. Many times it must react the measuring component before this reaction in an other reaction.
Boric acid is the reagent at the measure of the concentration of an ammonia content of a gas. I used this method in an industrial ammonia synthesis plant and I made many formula to measure different gas (for example hydrogen sulfide, carbon dioxide) and liquid (for example boric acid, blood glucose) components.
Dr. Endre Simonyi