Cette méthode n'est pas directement applicable à l'analyse du tritium organiquement lié; sa détermination nécessite un traitement chimique supplémentaire de l'échantillon (tel une oxydation chimique ou une combustion).

Dans les conditions techniques adéquates, la limite de détection peut être réduite à 1 Bq·l^-1. Les activités volumiques du tritium inférieures à 10⁶ Bq·l^-1 peuvent être déterminées sans dilution de l'échantillon.

The choice of the analytical procedure, either with or without distillation of the water sample prior to determination, depends on the aim of the measurement and the sample characteristics.

Direct measurement of a raw water sample using liquid scintillation counting has to consider the potential presence of other beta emitter radionuclides. To avoid interference with these radionuclides when they are detected, the quantification of tritium will be performed following the sample treatment by distillation. Three distillation procedures are described.

The method is not applicable to the analysis of organically bound tritium; its determination requires additional chemical processing (such as chemical oxidation or combustion).

With suitable technical conditions, the detection limit may be as low as 1 Bq l^–1. Tritium activity concentrations below 10⁶ Bq l^–1 can be determined without any sample dilution. A prior enrichment step can significantly lower the limit of detection.

This test method is applicable to the analysis of raw and drinking waters. The range of application depends on the amount of total soluble salts in the water and on the performance characteristics (background count rate and counting efficiency) of the counter used.

It is the laboratory's responsibility to ensure the suitability of this method for the water samples tested.

This test method is applicable to the analysis of raw and drinking waters. The range of application depends on the amount of total soluble salts in the water and on the performance characteristics (background count rate and counting efficiency) of the counter used. It is the laboratory's responsibility to ensure the suitability of this method for the water samples tested.

The method is applicable to the analysis of raw and potable waters.

La méthode est applicable à l'analyse des eaux brutes et des eaux potables.

La gamme de validité de la méthode dépend de la quantité de sels solubles totaux contenus dans l'eau et des caractéristiques de performance (taux de comptage du bruit de fond et rendement de comptage) du compteur.

Il incombe au laboratoire de s'assurer que cette méthode est adaptée aux échantillons d'eau soumis à essai.

The method is applicable to raw and potable waters.

The previously most employed method for assessment of water colour in water treatment plants, limnological surveys, etc. was based on the hexachloroplatinate scale. Methods C and D are harmonized with this traditional procedure.

Method A involves examination of apparent colour by visually observing a water sample in a bottle. This gives only preliminary information, for example for use in field work. Only the apparent colour can be reported.

Method B involves determination of the true colour of a water sample using optical apparatus and is applicable to raw and potable water and to industrial water of low colour. A subclause on interferences is included.

Method C involves determination of the true colour of a water sample using optical apparatus for comparison with hexachloroplatinate concentration at wavelength, ? = 410 nm. A subclause on interferences is included.

Method D involves determination of colour by visual comparison with hexachloroplatinate standard solutions and can be applied to raw and drinking water. A subclause on interferences is included.

Methods A and B are appropriate if the colour hue of the sample differs from the hue of the matching solution.

When stating the result, the procedure used (methods A to D) is also recorded.

a) measurement of visual range using the transparency testing tube (applicable to transparent and slightly cloudy water), see Clause 4;

b) measurement of visual range in the upper water layers using the transparency testing disc (especially applicable to surface, bathing water, waste water and often used in marine monitoring), see 5.1;

c) measurement of visibility by divers in a destined depth, see 5.2.

NOTE The quantitative methods using optical turbidimeters or nephelometers are described in ISO 7027-1.