BS EN 13373:2020,Natural stone test methods – Determination of geometric characteristics on units.BS EN 13373:2020 pdf free download.
5.2.4 Expression of the results
The average net dimension is expressed for each direction to the nearest 0, 01 m.
5.3 Measurement of the thickness ofa rough slab See 6.4(Measurement of the thickness and surface irregularities of finished products with sawn edges)
7. 2 [ Measurement of thickness and surface irregularities)
5.4 Measurement of the flatness of a rough slab
BS EN 13373:2020 describes methods for verifying the geometric characteristics of products of natural stone such as rough blocks, rough slabs, finished products for cladding, flooring, stairs and modular tiles and paving units (slabs, setts and kerbs). These methods can be applied in the case of a dispute between two parties, they are not compulsory for production control.
Other measuring equipment can be used as long as their precision can be demonstrated to be equal or better than the ones mentioned here.
It is essential that all weighing, measuring and testing equipment are calibrated or retraceable to measurement standards and regularly inspected according to documented procedures, frequencies and criteria. It is important that the expression of the dimensional characteristics is in accordance with the appropriate class of the measured product.
6.4.2 Expression of the results
The average thickness is expressed for each direction at 0, 1 mm
6.4.3 Measurement of surface irregularities
6.4.3.1 Principle
Measurement of surface irregularities for products with a textured surface finish(flame-textured, bush-hammered, etc and a sawn rear face).For products with a sawn surface finish or similar, measurement of surface irregularities is not required.