galvanic oxygen cell - how they work
galvanic oxygen cell supplied by hitech instruments ltd, luton england consists of galvanic oxygen cell type n, type l, type h and type e.
the is a diffusion limited metal/air battery. the oxygen in the sample diffuses through the barrier and reaches the cathode. here it is reduced to hydroxyl ions which, in turn, pass through the electrolyte to oxidise the metal anode.
a current, proportional to the rate of consumption of oxygen, is generated when the cathode/anode circuit is completed, the cell operating in what is virtually a short-circuit condition.
the cell current is a direct function of the rate at which oxygen reaches the cathode.
however type e operates in a slightly different way. this enable it to measure oxygen in samples containing high amount of carbon dioxide. it is linera up to 100% and provides a millivolt, rather than a current output.