ISO 1130:1975 pdf download – Textile fibres – Some methods of sampling for testing
No single technique of sampling can be devised that will serve in all circumstances. Sampling from a bale of cotton, for example, presents problems quite different from those encountered in sampling from a consignment of yarn packages, while sampling from a card web is again different from either. If the fibres in the bulk have been well mixed, so that there is no variation in composition from one part to another, ¡.e. the individual fibres are distributed at random, the sample can without disadvantage be taken from one place anywhere in the bulk. If the fibres in the bulk are not known to have been well mixed, so that the composition may vary from one part to another, a sample taken from any one place would not be representative of the whole bulk. A selection of methods is therefore presented, illustrating techniques that have been found acceptable in meeting the commoner types of problem encountered in sampling for the assessment of fibre quality. Methods peculiar to the requirements of research are not included, nor are such special techniques as have to be used, for example, in sampling of wool from the fleece, or cotton from the seed.
This International Standard specifies several methods for preparing laboratory samples of fibres, and presents a limited treatment of the problem of drawing specimens for test i ng . The field of application of each method is given a t the beginning of the clause dealing with the method. It is not possible for the coverage of each individual procedure to be fully comprehensive; in many instances, the selection of test samples or test specimens must necessarily be covered by the appropriate method of test. The selection of length-biased samples is not within the scope of this International Standard, nor are particular requirements relating to the determination of commercial weights.
2.1 individual : Any single fibre that might be taken for the purpose of measurement.
2.2 population : The aggregrate of individuals that it is desired to characterize in one or more particulars (for example : fibres contained in a bale of cotton; all the constituent fibres in a set of yarn cops).
2.3 zoning : When the population to be sampled is known to vary from part to part with respect to the property to be investigated, the individuals or groups of individuals in the population are taken a t random from within the different parts or zones, chosen so that all variations of the property are represented in due proportion. This operation is known as zoning.
2.4 laboratory sample : A sample intended to be representative of a large bulk of material, in the state in which it is sent to the laboratory. A convenient size of sample for many types of test involving only small test specimens i s about 25 to 50g; a larger amount will be required for tests involving relatively large test specimens.
2.5 laboratory test sample : That portion of fibres taken from the laboratory sample in such a way as to ensure i ts representative character and to provide a quantity small enough to be easily convertible into test specimens.