AS1141-11-2-2008 国外国际规范.pdf

1 AS 1141.11.2—2008 Australian Standard® A S 1 1 4 1 Methods for sampling and testing aggregates . 1 1 . 2 — Method 11.2: Particle size distribution for vision 2 0 0 sizing systems 8 1 SCOPE This Standard sets out the method for the determination of particle size distribution in coarse and fine aggregates by vision systems. The VSS is limited by the discrimination of the optical system and, at present, is suitable for materials coarser than 1.18 mm. A calibration procedure is required to relate results from this procedure to particle distribution by sieving (AS 1141.11). NOTE: A summary of VSS technology is given in Appendix A. 2 APPLICATION AS 1141.11 measures particle size distribution of a sample on the basis of mass of sample passing or retained on the square or round hole sizes of the AS 1152 screens used. VSS measures the length dimensions of images of particles in two dimensions, and derives a third dimension. VSS does not measure mass and, hence, variations in particle density in particles within a sample or between samples, will cause a difference in calculating the particle size distribution between the two methods. Some of this difference can be reduced by ‘source calibration’ especially where the VSS is used in an ‘in-plant’ appli