scope:

NEN-ISO 13322-1 is applicable to the analysis of images for the purpose of determining particle size distributions where the velocity of the particles against the axis of the optical system of the imaging device is zero. The particles are appropriately dispersed and fixed in the object plane of the instrument. The field of view may sample the object plane dynamically either by moving the sample support or the camera provided this can be accomplished without any motion effects on the image. Captured images can be analysed subsequently. This part of ISO 13322 concentrates upon the analysis of digital images created from either light or electron detection systems. It does not address the method of creating the image although the detection settings chosen together with its calibration are important to particle sizing accuracy. This part of ISO 13322 considers only image evaluation methods using complete pixel counts. Both the type of distribution, (by number or by volume) together with the width of the particle size distribution has a very material influence upon the number of particles to be measured to secure the desired accuracy within the specified confidence limits. An example is shown in Annex A. Automation of the analysis is possible in order to measure sufficient particle numbers for a required degree of precision. This part of ISO 13322 does not address the sample preparation. However, the sub sampling, dispersion and presentation of particles to be measured are a vital part of the operational chain of actions necessary to ensure accuracy and precision of any final result.