This European Standard describes the reference method used for type testing and in cases of dispute for determining the particle size distribution up to 2 mm size of natural or manufactured origin filler aggregate using air jet sieving. For other purposes, in particular factory production control, other methods may be used provided that an appropriate working relationship with the reference method has been established. NOTE A wet sieving procedure conforming to EN 933-1 can be used as an alternative method. However, this procedure is not applicable for mixed filler.