1.Prescribes two methods for determination of total hardness, namely:
a) Ethylenediamine tetraacetic acetate acid ( EDTA) method, and
b) Method based on analytical data.
1.1 The first method is based on the reaction of calcium and magnesium salts with ethylenediamine tetra acetic acid or its disodium salt and is applicable to all types of water but not applicable to waste water. The analytical data method is based on computation from analytical results of the sample and is applicable to water and waste water. In case of dispute, the method based on analytical data shall be used.
IS 3025 Pt.21-1983 history
1985IS 3025 Pt.21-1983 Methods of sampling and testing of water and wastewater (physical and chemical) Part 21 Total hardness