ORP (Oxidation-Reduction Potential) is a term used frequently in the water treatment & food processing industry. It is a measure of the cleanliness of the water & its ability to break down contaminants. ORP sensors work by measuring the dissolved oxygen i.e. if contaminants in the water are more it results in less dissolved oxygen because the organics are consuming the oxygen and the ORP level is low. The higher the ORP level, the more ability the water has to destroy foreign contaminants such as microbes, or carbon based contaminants. ORP level can also be viewed as the level of bacterial activity of the water because a direct link occurs between ORP level and Coli form count in water. This instrument is ideal for testing liquids like natural water, drinking water, treated water, waste water, brine solution, sea water and soluble salt content in liquids.