Reaffirmed 2023

1. Scope

1.1 This standard prescribes two methods for determination of total hardness, namely (a) Ethylenediamine tetraacetic acetate acid (EDTA) method, and (b) Method based on analytical data and also the methods for determination of carbonate and non-carbonate hardness.

1.2 The EDTA method is based on the reaction of calcium and magnesium salts with ethylenediamine tetraacetic acid or its disodium salt and is applicable to all types of water but not applicable to wastewater. 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.

2. References

The Indian Standards listed below contain provisions, which through reference in this text constitute provisions of this standard. At the time of publication, the editions indicated were valid. All standards are subject to revision and parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below:

IS No. Title

3025 Methods of sampling and test (physical and chemica1) for water and waste water:

(Part 1) : 1987 Sampling (first revision)

(Part 23) : 1986 Alkalinity (first revision)

7022 Glossary of terms relating to water, sewage and industrial effluents:

(Part 1) : 1973 Part 1

(Part 2) : 1979 Part 2