Abstract:
An electrochemical cell for determining a constituent in a sample in which a pair of electrodes are joined by an electrolyte and separated from the sample by a selectively permeable membrane. A perforated plate overlying the membrane adjacent to the sensing electrode of the cell is spring biased toward said electrode. As a consequence, when the cell is subjected to a vacuum environment, the spring biased perforated plate will prevent alterations in the thickness of the electrolyte film space between the membrane and sensing electrode or bursting of the membrane due to the relatively higher pressure within the cell. The cell is stable in a vacuum environment and has fast response when utilized at low sample gas pressure.