Rechercher

Gives general intructions and specifies the methods for the determination of density at 20 °C, for the determination of boiling range, for the determination of dry residue after evaporation on a water bath, for the measurement of colour, for the determination of water content and of aldehydes and ketones content. International Standards ISO 756/1, ISO 756/2 and ISO 756/3 cancel and replace ISO…

The principle consists in dilution of a test portion with carbon dioxide-free water, titration of the acidity with standard volumetric sodium hydroxide solution, in the presence of phenolphthalein as indicator. The method is applicable to products having an acidity, expressed as acetic acid, equal to or greater than 0,0006 % (m/m).

Specifies the method of measuring the pressure drop across a fluid filter under various conditions of flow. Two standards of measurement are specified: class A - for accurate evaluation for referee purposes - requiring laboratory conditions; class B - for evaluation for general purposes - requiring test facilities less stringent that laboratory conditions. Figure 1 shows an example for a suitable…

Specifies the requirements of refined copper listed in table 1, in the form of refinery shapes (unwrought products). The refinery shapes included are cathodes, horizontally, vertically and continuously cast wire bars, cakes, billets and ingots. This second edition cancels and replaces the first edition (i.e. ISO 431-1972), the ISO Recommendations R 1428, R 1429, and R 1430, and the International…

The sample is oxidized by nitric and sulphuric acids or by the use of Eschka mixture. Then, using the method specified in ISO 2590, the arsenic is reduced by zinc in sulphuric acid or hydrochloric acid medium. The arsine formed is absorbed in a solution of silver diethyldithiocarbamate in pyridine. The purplish-red colour produced by the colloidally dispersed silver is measured photometrically at…

The principle consists in the treatment of a test portion with aniline and acetic acid, the presence of furfural leading to the formation of a characteristic red colour. - International Standards ISO 1388/1 to ISO 1377/12 cancel and replace ISO Recommendation R 1388-1970 of which they constitute a technical revision.

The principle is based on the addition of a test portion, under specified conditions, of potassium permanganate solution. Determination of the time taken for the colour of this test solution to match that of a cobalt(II) chloride and uranyl nitrate colour standard. - International Standards ISO 1388/1 to ISO 1377/12 cancel and replace ISO Recommendation R 1388-1970 of which they constitute a…

The method is applicable to products having esters contents in the range 0.005 % (m/m) to 0.15 % (m/m). The principle consists in the saponification of esters present in a test portion by boiling with excess standard volumetric sodium hydroxide solution; determination of the residual sodium hydroxide, and hence the amount used for saponification, by titration with standard volumetric hydrochloric…

The method is applicable to products having carbonyl compounds contents between 0.00025 % (m/m) and 0.01 % (m/m). The principle is based on reaction in acid medium of the carbonyl compounds in a test portion with 2,4-dinitrophenylhydrazine. Formation of the corresponding 2,4-dinitrophenylhydrazones which, after making the solution alkaline, take on a red coloration. Photometric measurement of…

The method is applicable to products having carbonyl compounds contents equal to or greater than 0.01 % (m/m). The method only allows determination of those carbonyl compounds which react under the specified conditions. The principle is based on the reaction of hydroxylammonium chloride with the carbonyl compounds in a test portion and titration of the hydrochloric acid formed with standard…