Amperometric sensor probe for an automatic halogen control system

A method of treating water at a site having a water feature comprising:

• providing a concentration of a sanitizing agent in water within the water feature;
• passing water from said water feature across respective portions of a first electrode and a second electrode;
• applying a sequence of different voltages between said first electrode and said second electrode while said electrode portions are in contact with said aqueous solution;
• measuring the concentration of the sanitizing agent in the water at the water feature site using said first electrode and said second electrode, said measuring comprising applying one of said different voltages between said first electrode and said second electrode during a time interval spanning a first time and a second time, and determining the current between the electrodes at said second time, wherein said first time and said second time are separated by a substantial time interval;
• using the measured concentration of the sanitizing agent in the water to maintain the concentration of the sanitizing agent within a preset range;
• and
• utilizing at least two of said different voltages between said first electrode and said second electrode to clean said first electrode.