Continuous monitoring of gas streams:
Determination of trace level concentration of oxygen within a gas stream could be completed through controlled potential analysis. The cell consists of a porous silver cathode and a cadmium anode. The reactions are
O2 (g) + 2H2O + 4e- ? 4 OH- (cathode)
Cd(s) + 2OH- ? Cd(OH)2(s) + 2e . (Anode)
The porous silver cathode serves to break up the incoming gas within small bubbles, whereas the decreasing of oxygen takes place quantitatively inside the pores. The hydroxyl ions created during reduction reacts along with the cadmium anode and forms a Cd(OH)2(s) product.