Dyeing effluents, for example, can contain concentrations of some heavy metals such as chromium and copper, but also zinc, lead, and nickel.Use the handheld Ultrameter II 4P or 6P, TechPro II TP1 or TPH1, or DS/pDS meter to manually test TDS/Conductivity and Salt Concentration, cooling the water to the prescribed parameters for the instrument, if necessary.