ISO 3129:1975

Specifies the selective and mechanical sampling, conditioning of selected material and the preparation of test pieces. Selective method should be used in cases where the coefficients of variation of the wood properties for one tree and between trees of one species are known and selection is possible from a large number of trees, logs and pieces of sawn timber, and the mechanical method when the mean values of the above coefficients are known and selection is possible only from a limited number of trees, logs and pieces of sawn timber.