Why choose amperotric control instead of ORP control ?
Unlike amperometric measurement, ORP does not, strictly speaking, quantify chlorine concentration. It measures all the oxidising products in the water. There is therefore no selectivity. What’s more, it is highly dependent on water quality, pH, temperature and stabiliser.
In other words, ORP measurement is used to assess the health of the water, not the level of free chlorine actually present in the water.