The test is carried out using aggregate particles that pass a 10.0 mm test sieve but are retained on a flake sorting sieve with slots of width 7.2 mm. The particles are fixed in resin blocks and subjected to polishing in a standard polishing machine, using first corn emery (0.3/0.5 mm) with water, then emery flour (0/0.05 mm) with water, to wear the exposed faces of the aggregate particles. The degree of polish reached by the particles is then measured using a standard friction tester.
The CEN test method has been developed from the British Standard BS 812 Part 114 1989, and is the same, in all essential respects, as the British method. Participants in the cross-testing experiment were sent copies of the method that was sent to CEN members for CEN Enquiry in April, 1995.