BS EN ISO 3071:2020 pdf free.Textiles – Determination of pH of aqueous extract.
BS EN ISO 3071 This document specifies a method for determining the pH of the aqueous extract of textiles. The method is applicable to textiles in any form e.g. fibres, yarns, fabrics).
2 Normative references The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.ISO 3696, Water for analytical laboratory use一Specification and test methods.The pH shall be verified the first time the water is used. If it is not within the specified range, the water shall be redistilled using chemically resistant glassware. Acid or organic matter can be removed by distilling water from a solution of 1 g/l potassium permanganate and 4 g/l sodium hydroxide. Alkalinity (e.g. the presence of ammonia) can be removed by distilling the water from a solution of dilute sulfuric acid. If the distilled water is not grade 3, boil 100 ml of distilled water in a beaker at a moderate rate for (10土1) min and allow the covered beaker to cool to room temperature.Immerse the electrode several times in the KCl solution used to prepare the extract until the indicated pH-value stabilizes. Decant a portion of the first extract into a beaker, immediately immerse the electrode to a depth of at least 10 mm and stir gently with a rod until the pH-value stabilizes (do not record the pH-value of
this solution). Decant the remaining first into another beaker, immediately immerse the electrode, without washing, in the beaker to a depth of at least 10 mm and allow to stand without stirring until the pH-value stabilizes.Record this value as the first measurement.Decant the second extract into another beaker, immediately immerse the electrode, without washing, in
the beaker to a depth of at least 10 mm and allow to stand without stirring until the pH-value stabilizes.Record this value as the second measurement.BS EN ISO 3071 pdf download.