| 摘要 |
A method of measuring oxidant in an aqueous composition using an electrode system 10 comprising a membrane 26 permeable to a species to be measured, a cathode 34 situated behind the membrane, and an electrolyte between the membrane and cathode, the method comprises contacting the membrane and an anode 14 with the aqueous composition and measuring the current in response to a first voltage, then applying a pulse of a second voltage that is different from the first voltage. Preferably the pulse is applied when the electrode system is in contact with a chlorine free aqueous composition, the electrode system may be in contact with said composition for at least 1 hour, more preferably at least 5 hours, the pulse may be applied multiple times. Also disclosed is an apparatus for measuring free chlorine in an aqueous composition comprising an electrode system comprising an electrolyte chamber comprising a hypochlorous permeable membrane and a cathode situated behind the membrane; a power supply which applies a first voltage and a pulse of a second voltage, wherein the second voltage is different from the first voltage and a current detector that measures the current in response to the first voltage. |
