IS 3025 : Part 10 : Sec 2 : 2024/ISO 7027-2 : 2019 Methods of Sampling and Test (Physical and Chemical) for Water and Wastewater - Part 10 Turbidity - Section 2 Semi-Quantitative Methods for the Assessment of Transparency of Waters
NATIONAL FOREWORD
This Indian Standard (Part 10/Sec 2) which is identical to ISO 7027-2 : 2019 'Water quality - Determination of turbidity - Part 2: Semi-quantitative methods for the assessment of transparency of waters' issued by the International Organization for Standardization (ISO) was adopted by the Bureau of Indian Standards on the recommendation of Water Quality Sectional Committee and approval of the Chemical Division Council.
Turbidity in waters is caused by the presence of undissolved and/or colloidal matter and small organisms (for example bacteria, phytoplankton and zooplankton) present in the water.Turbidity changes the lighting conditions in surface waters by absorption and scattering of the light and thus influences the trophic status of these waters. For the indicative assessment of the lighting conditions of waters or the transparency of the water, semi-quantitative methods can be used.
The Indian Standard IS 3025 : 1964 'Methods of sampling and test (physical and chemical) for water used in industry' prescribes the methods of test for various parameters in water and wastewater. The Committee responsible for formulating this standard has decided to harmonize the methods of test prescribed in IS 3025 with those prescribed in ISO standards. Accordingly, the committee decided to retain IS 3025 and publish the harmonized/ adopted test methods published by ISO in various parts of IS 3025 as this standard is widely recognized by water testing laboratories. The committee had further decided to publish the new test methods adopted/harmonized standards as a new standard and as a subsequent part/section of IS 3025.
The Committee responsible for formulation of IS 3025 (Part 10) had decided to publish this standard as IS 3025 (Part 10/Sec 2). IS 3025 (Part 10/Sec 1) prescribes nephelometric method for determination of turbidity in water and wastewater.
The text of ISO standard has been approved as suitable for publication as an Indian Standard without deviations. Certain conventions are, however, not identical to those used in Indian Standards. Attention is particularly drawn to the following:
a) Wherever the words 'International Standard' appears referring to this standard, they should be read as 'Indian Standard'; and
b) Comma (,) has been used as a decimal marker, while in Indian Standards, the current practice is to use a point (.) as the decimal marker.