scope:

In the methods given in this International Standard, thelaboratory test samples are obtained by the combination of numeroussmall portions each drawn from a different part of thelaboratory-bulk Sample. Therefore, any results obtained on testspecimens from these samples will estimate the mean level in thelaboratory bulk Sample but will not indicate the variability oflevel from Portion to Portion of the laboratory bulk Sample.Consequently it is appropriate to use this method in cases where itis. desired to estimate the bulk composition, for example theproportions of different fibres in a blend, but it is notappropriate in cases where variability is important, for example inthe determination of pH where the local value is significant, or inthe determination of fungicides, where a high value in one area ofthe material does not compensate for a low value elsewhere. Nor mayit be appropriate .for use in determination of commercial massvalues.