ISO 3071-2020 pdf free.Textiles — Determination of pH ofaqueous extract.
This document specifies a method for determining the pH of the aqueous extract of textiles.The methodis applicable to textiles in any form (e.g. fibres, yarns, fabrics).
The following documents are referred to in the text in such a way that some or all of their contentconstitutes requirements of this document.For dated references,only the edition cited applies. Forundated references, the latest edition of the referenced document (including any amendments] applies.ISO 3696, Water for analytical laboratory use — Specification and test methods.
For the purposes ofthis document, the following terms and definitions apply.
The pH-value of an aqueous extract of a textile is measured electrometrically at room temperature bymeans of a glass electrode.
All reagents used shall be of recognized analytical grade. Distilled or deionized water, of at least grade 3 as defined in ISO 3696, having a pH between 5,0and 7,5.The pH shall be verified the first time the water is used. If it is not within the specified range, the watershall be redistilled using chemically resistant glassware.Acid or organic matter can be removed bydistilling water from a solution of 1g/l potassium permanganate and 4g/l sodium hydroxide.Alkalinity(e.g. the presence of ammonia) can be removed by distilling the water from a solution of dilute sulfuricacid. If the distilled water is not grade 3,boil 100 mlof distilled water in a beaker at a moderate rate for[10±1) min and allow the covered beaker to cool to room temperature.
Potassium chloride solution, 0,1 mol/l, prepared using distilledor deionized water (5.1).
Buffer solutions, which may be prepared as specified in Annex A. or obtained commercially,having a pHsimilar to that being determined, for calibration of the pH-meter before measurement. Buffersolutions having a pH around 4,7 or 9 are recommended.Stoppered glass or polypropylene flasks, chemically resistant, for preparation of the aqueousextract.lt is recommended that the glassware used for this test be set aside for this purpose only.SO 3071 pdf download.