The certification of particle size distribution of corundum : ERM-FD066

This report describes the production of ERM-FD066, which is a corundum material certified for the particle size distribution as determined by laser diffraction (ISO 13320) and scanning electron microscopy (ISO 13322). This material was produced following ISO Guide 34:2009 and is certified in accordance with ISO Guide 35:2006. Commercial corundum was ground, mixed, riffled and packed into glass bottles. These bottles are equipped with three flow breakers to allow homogenisation of the individual sample. Between unit-homogeneity was quantified and stability during dispatch and storage were assessed in accordance with ISO Guide 35:2006.The minimum sample intake was determined as the lowest amount that gave repeatable results in the characterisation study. The material was characterised by an interlaboratory comparison of laboratories that demonstrated competence and adhering to ISO/IEC 17025. Technically invalid results were removed but no outlier was eliminated solely on statistical grounds. Uncertainties of the certified values were calculated in accordance with the Guide to the Expression of Uncertainty in Measurement (GUM) and include uncertainties related to possible inhomogeneity, instability and characterisation. The material is intended for the quality control and assessment of method performance. As with any reference material, it can be used for establishing control charts or validation studies. The CRM is available in glass bottles containing at least 40 g of corundum powder. The minimum amount of sample to be used is 70 mg.