This International Standard specifies requirements for test sieves to be used for the laboratory determination of undesirable substances in a sample of cereals and which pass through test sieves of the following nominal sizes: a) test sieves with long rounded apertures: 1,00 mm × 20,0 mm 1,70 mm × 20,0 mm 1,80 mm × 20,0 mm 1,90 mm × 20,0 mm 2,00 mm × 20,0 mm 2,20 mm × 20,0 mm 2,50 mm × 20,0 mm 2,80 mm × 20,0 mm 3,55 mm × 20,0 mm b) test sieves with round apertures: diameter 4,50 mm Test sieves with long rounded apertures listed in a) are used in particular for separating "shrivelled" kernels from rye, durum wheat, common wheat and barley, with the exception of those with apertures of diameters 2,50 mm and 2,80 mm, which are usually used for the calibration of malting barley. Test sieves with round apertures of diameter 4,50 mm are used for separating broken grains from maize. This International Standard does not apply to test sieves used for testing grain for insect infestation.