The Polydisperse particle standards formally known as the BCR 'Mirror' standards were made both to assess the performance of the analytical laboratories and to augment a limited supply of the official standards. Although sub-divided, the BCR samples were never certified, which leaves these new polydisperse particle standards as the most comprehensively analysed set of spherical particle size reference standards available.

• Calibration for any method of particle size analysis
• Unambiguous primary methods used - microscopy, sieving, sedimentation and the Coulter method

Traceability through NIST, BCR and NPL standards.