Analysing free chlorine content of chlorinated water - by amperometric cell with copper electrodes contacting flowing sample

摘要

A sample stream from a chlorinated water supply is passed through a cell without the addition of buffering agents. The cell includes a copper measuring electrode and a copper counter-electrode making contact with the sample stream. A direct voltage is applied across the electrodes with the measuring electrode being negative with respect to the counter-electrode and with the applied voltage causing the cell to operate in a saturation voltage zone. In this zone the current flow is proportional to the chlorine content and is independent of small changes in the applied voltage. The current flow is indicated on a meter calibrated in chlorine concentration. Preferably the meter reading is temperature compensated by the use of a shunt thermistor. The apparatus provides a continuous indication of free chlorine in a swimming pool. The use of buffering agent is eliminated and the electrodes remain active for a prolonged period.