Reference number
ISO 2174:1990
ISO 2174:1990
© ISO 2024
International Standard
ISO 2174:1990
Surface active agents — Preparation of water with known calcium hardness
Edition 3
1990-04
1990-04
ISO 2174:1990
6972
Published
(Edition 3, 1990)
This publication was last reviewed and confirmed in 2021.
Therefore this version remains current.
Abstract
A stock solution is prepared by dissolving an appropriate quantity of calcium chloride in water. The calcium content of this stock solution is determined by complexometric titration with the disodium salt of (ethylenedinitrilo)tetraacetic acid (EDTA) using a mixture of Mordant Black 11 (C.I. 14645) and methyl red as indicator. Dilute solutions of the hardness required are prepared by dilution of appropriate volumes of the stock solution.
Life cycle
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Previously
WithdrawnISO 2174:1979
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Now