Voltage bands for electrical installations of buildings
Applies to a.c. electrical installations of buildings supplied at a frequency not exceeding 60 Hz and at a nominal voltage up to and including 1 000 V. Defines two voltage bands: Band I covers the installations where protection against shock is provided under certain conditions by the value of voltage and the installations where the voltage is limited for operational reasons (e.g.…
Sodium chloride for industrial use — Determination of matter insoluble in water or in acid and prepa...
Insoluble substances shall be defined by the conditions described in this document. The object is not to dissolve all the impurities but only those of interest to users. The method is applicable to the analysis, carried out inaqueous medium or in acid medium. The principle consists in solution of the test portion in water, filtration, drying and weighing of the insoluble residue. Dilution of the…
Sodium chloride for industrial use — Determination of sulphate content — Barium sulphate gravimetric...
The method is applicable to water soluble sulphate, in the product, but also to sulphates in a principal solution prepared in an acid medium. The principle consists in dissolution of a test portion and separation of the insoluble residue. Precipitation of the sulphate ions by barium chloride in a boiling acid medium. Filtration, washing and ignition of the precipitate. Weighing of the residue.
Aluminium fluoride for industrial use — Determination of iron content — 1,10- Phenanthroline photome...
The method is applicable to products having a content greater than 0,020 %. The principle consists in dissolution of a test portion by either alkaline or acid fusion. Reduction of the iron(III) by hydroxylammonium chloride. Formation of the iro(II)-1, 10-phenanthroline complex in a buffered medium (pH value between 3,5 and 4,2) Photometric measurement of the coloured complex at a wavelength of…
Aluminium fluoride for industrial use — Determination of silica content — Spectrophotometric method ...
The method can be applied provided the phosphorus pentoxide content does not exceed 0,02 % (m/m). The principle is based on alkaline fusion of a test portion by means of a mixture of sodium carbonate and boric acid. Solution of the fused mass in excess nitric acid so that the pH of the final solution is between 0,3 and 0,5 after being diluted. Formation, in a suitable aliquot portion, of the (…
Ammonium nitrate for industrial use — Determination of free acidity — Volumetric method
The principle of the analysis consists in titration of a test portion with a standard sodium hydroxide solution in the presence of methyl red/methylene blue mixed indicator.
Aluminium fluoride for industrial use — Determination of fluorine content — Modified Willard-Winter ...
The principle of the method consists in fusion of a test portion with sodium carbonate. Separation of fluorine by distillation with sulphuric acid. Titration with thorium nitrate solution using sodium alizarinsulphonate-methylene blue as indicator. Alternatively, the thorium nitrate titration may be made using only sodium alizarinsulphonate; the end-point being spectrophotometrically determined…
Formaldehyde solutions for industrial use — Limit test for inorganic chlorides
The method, as specified, is applicable when the required limit is not greater than 0,05 % and not less than 0,0005 %. If the required limit lies outside that range, the mass of the test portion should be changed. The principle of the test consists in comparison of the turbidity obtained by the addition of silver nitrate solution to a solution of the sample, in the presence of nitric acid, with…
Formaldehyde solutions for industrial use — Limit test for inorganic sulphates
The specified method is applicable when the required limit is not greater than 0,1 % and not less than 0,001 %. If the required limit lies outside that range, the mass of the test portion should be changed. The principle ot the test consists in comparison of the turbidity obtained by the addition of barium chloride solution to a solution of the sample, in the presence of hydrochloric acid, with…
