Investigation on different variation factors in the results of mycological test and means to reduce and avoid them
In order to clarify the causes of the dispersion observed in the results obtained with mycological tests made in accordance with standard EN-113, different factors assumed to be sources of the variations were studied. These included the moisture content of the test samples during the test, the influence of certain technological properties of the wood, the virulence of the fungus strains, the method by which the test pieces were treated and the effect of the solvent, and behaviour of the wood fungus in contact with the wood preservative. It turns out that certain factors which were supposed to be important are actually secondary (humidity). On the other hand, the virulence of the strains is a major problem and requires a serious examination. Treatment by dipping with a ready-to-use product might avoid errors due to obligatory dilutions. In the end, wood species other than beech and Scots pine be used. However, one must not lose sight of the fact that there is a risk that the toxic values may not always be identical.