Glass electrode for analysing gaseous specimens - having uniform electrolyte film for accuracy under non-equilibrium conditions

摘要

In an electrochemical cell for potentiometrically analysing gaseous specimens in which the specimen permeates a thin, flexible, semipermeable membrane of microporous polypropylene and dissolves in a thin film of electrolyte confined between the membrane and a pH sensitive sensor tip, causing a measurable pH change in the electrolyte, the outer surface of the sensor tip is convex with a radius of curvature of 1-2.5 in. and is attached to a chemically-resistant glass tube about 1/3 in. dia. at the point of attachment to define the height of the arc of the tip in the range 5-15 mil, thus ensuring that the confined electrolyte film is of uniform thickness across the surface of the sensor tip. The uniform electrolyte layer ensures accurate analysis when operating in a non-quilibrium mode. The uniformity is maintained even under snug engagement conditions.