Test Method DTM09 - Water Hardness

This dropper test method (DTM) is suitable for the field determination of the total hardness of any water source used for the preparation of cleaning solutions e.g. town mains; borehole etc The method is based on the chelation or sequestration of the (divalent) water hardness metal ions calcium and magnesium, with the endpoint detected by a combined solochrome black indicator and buffer. It covers water hardnesses from 0 to 600ppm (expressed as calcium carbonate, CaCO3).