Hersch cell

Numerous commercial oxygen analysers are available, based on the principle of the Hersch cell, but all being protected from the analyte medium, either gaseous or liquid, by means of a membrane (usually Teflon). This membrane detector is known as the Clark cell (see later under membranes as measurement aids, p. 352) for gas analysis we may mention the Beckman Models 715 (also for liquids), 741, 743 (for flue gas), 755 and 778119. 

A galvanic cell-type (Hersch cell) coulometer consists of a platinum (Pt) cathode, KBr (or KI) electrolyte (stripping solution), and active carbon anode. When air containing ozone is bubbled into the solution, the bromine (or iodine) liberated by the ozone is reduced at the Pt cathode and hydroxide ion discharges at the carbon anode ... 

Klement IA, Skinner PJ, Kaytor MD, Yi H, Hersch SM, Clark HB, Zoghbi HY, Orr HT. Ataxin-1 nuclear localization and aggregation role in polyglutamine-induced disease in SCA1 transgenic mice [see comments]. Cell 1998 95 41-53. 

Figure 6.8 Hersch galvanic cell for the determination of oxygen at trace levels in gases.

---