NBN EN 1309-3:2018

This European Standard specifies the methodology for measurement of features - in relation to wood structure, biological agencies and other damage - taken into account in the visual grading:
a) for appearance - of sawn, processed and round timber;
b) for serviceability - of sawn and processed timber (identified in EN 1611-1 as the integrity of the timber).
When the standard is applied the methodology of measurement used shall be stated.
It is not applicable to structural timber for which strength grading in accordance with EN 14081-1 is required.
This standard applies to hardwood and softwood sawn timber, both square edged and un-edged, to processed timber and to round timber.
It does not apply to tropical timber.