BS EN ISO 9455‑3:2020 pdf download.Soft soldering fluxes — Test methods.
1 Scope
This document specifies two methods for the determination of the acid value of a flux of types 1 and 2 only, as defined in ISO 9454-1.
Method A is a potentiometric titration method and is to be considered as the reference method.
Method B is an alternative, visual end-point, titration method.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
No terms and definitions are listed in this document.
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4.2.2 Propan-2-ol [(CH 3 ) 2 CHOH], neutralized with tetrabutyl ammonium hydroxide solution (4.2.1) to a faint pink colour, using phenolphthalein as indicator.
4.2.3 Ethanol (C 2 H 5 OH), anhydrous, neutralized with tetrabutyl ammonium hydroxide solution (4.2.1) to a faint pink colour using phenolphthalein as indicator.
4.2.4 Toluene (C 6 H 5 CH 3 ), neutralized with tetrabutyl ammonium hydroxide solution (4.2.1) to a faint pink colour using phenolphthalein as indicator.
4.2.5 Ethanol/toluene mixture, made by mixing equal volumes of the anhydrous ethanol (4.2.3) and toluene (4.2.4).
4.3 Apparatus
Usual laboratory apparatus and, in particular, the following.
4.3.1 Millivoltmeter or pH meter.
4.3.2 Glass electrode.
4.3.3 Saturated calomel, or silver chloride/silver, electrode.
4.3.4 Magnetic, or mechanical, stirrer, with variable speed drive.
4.3.5 Automated titration system with evaluating processor unit.
4.4 Procedure
4.4.1 General
By preliminary experiments, determine whether the sample is soluble in propan-2-ol, anhydrous
ethanol, toluene or the ethanol/toluene mixture. If it is not completely soluble in any of these solvents,select the one in which it appears to be the most soluble. If it is equally soluble in all four solvents, then use propan-2-ol.
5.2 Reagents
Use only reagents of recognized analytical quality and only distilled, or deionized, water.
5.2.1 Ethanol, anhydrous, neutralized with potassium hydroxide, 0,1 mol/l in alcohol (5.2.5), to a
faint pink colour using phenolphthalein as indicator.
5.2.2 Toluene, neutralized with potassium hydroxide, 0,1 mol/l in alcohol (5.2.5), to a faint pink colour using phenolphthalein as indicator.
5.2.3 Ethanol/toluene mixture, made by mixing equal volumes of the anhydrous ethanol (5.2.1) and toluene (5.2.2).
5.2.4 Propan-2-ol, neutralized with potassium hydroxide, 0,1 mol/l in alcohol (5.2.5), to a faint pink colour using phenolphthalein as indicator.BS EN ISO 9455‑3 pdf download.