a 2. Only for tiles with individual facial areas ≥ 4 cm. b. At least 1 m2 with a minimum of 30 tiles. Whatever the number of tiles 1 m2, the test sample should be the nearest 10 tiles. above. Conformity to AQL 2.5 ٪ in accordance with ISO 2859 or 3951 is acceptable alternative to the. procedures in Table 1. c.