Grading and scaling regulations for forestry products
(sawlogs and pulpwood)

DEFINITIONS

Developed by "Tømmermålingsforeningenes Fellesorgan" (TMF) and sanctioned by FUNT 12.03.98.
Effective 01.08.98.
Replacing "Forskrift for måling av skogvirke (hoveddel)
vedtatt av Tømmermålingsrådet 28. mai 1990".

Abatement of diameter or length. Reduction of the measures of the length or diameter to compensate for defects and irregularities on the log.

Angled crook. A log has an angled crook when the centreline of the log forms an angle.

Aniline coloured wood. Wood coloured by decay fungi, without appreciably changing the original strength properties of the wood. For spruce often initiation of wood destroying decay. Colour is gray-violet and the fungi often forms a ring.

Annual ring width. If nothing else is determined the annual ring width is measured on the average diameter on the top end of a log.

Automatic grading and scaling. Measurement of log length and diameter on bark by means of optical- electronical devices. Diameter under bark computed by means of bark-reduction functions. Log quality and eventual abatement is determined visually by the grader.

Average diameter. Average of the smallest and largest diameter at a right angle to the length direction of the log.

Bark abatement. Reduction of diameter registered on bark; as estimated judgement by the use of calliper or computed on the basis of the bark-reduction function when optical electronical equipment is being used.

Bark pocket. Damage of bark and cambium, eventually also in the stemwood, stopping ordinary wood formation. May be more or less overgrown, and is classified as open or overgrown bark pockets. A bark pocket is not overgrown untill the annual rings (the wood) have closed over the bark pocket.

Bark-reduction function. Mathematical function to compute the double thickness of the bark on the basis of the log diameter measured on the bark. Functions have been developed for thin, normal and thick bark for spruce and for shiny bark, transition bark and rough bark for pine.

Barkringed knot. Sound, dead or rotten knot whole or partly surrounded by bark growing along the knot into the log.

Black knot. Dead knot.

Buttresses. Part of the root comes with the log when the felling cut is positioned very low on the stump and which may cause difficulties in further processing.

Butt crevices. Deep depressions with ridges between at the butt end of a butt log. The depressions may be so deep that they influence the top-cylinder.

Cleft. Occurs by cutting of a stem which has developed two top-ends. See also Double pith. The smallest stem part must a diameter of minimum 1/3 of the diameter of the main stem for the log to be regarded as being clefted. If the smaller part is smaller it is regarded as a knot (branch).

Collective. Collection of grading and scaling objects (loads/lots) similar with regard to grading and scaling methods, registration methods and group of assortments, graded and scaled within a defined timespan.

Compression wood, dense compression wood. Hard, redbrown reaction wood with wide annual rings formed as a result of exterior influence on the tree. Often leads to eccentricity in the cross section of the log. The colour is most often darker than normal wood. Open compression wood is compression wood where the late wood in each annual ring is narrower than in the early wood. Dense compression wood is compression wood where the late wood in each annual ring is as wide as or wider than in the early wood.

Control - measurement. Measurement of earlier measured objects done by the inspector or the control-grader of the grading association to ascertain the performance of the grading and scaling with regard to volume, value and quality estimations.

Convenient diameter measure. Convenient diameter measure means that the diameter is measured horizontally and at a right angle to the log length as the log is placed.

Crook. A log has a crook when the centreline is not following a straight line.

Crosswise measurement. Measurement of diameter in more than one direction, usually two measurements at right angle, in order to find the average diameter.

Cut off at right angles. Log ends are even for at least 2/3 of the end area, the undercut does not extend more than 1/3 of the diameter into the log or up the stem. An eventual felling comb is not to be more than 5 cm tall.

Dark decay. Decay is regarded as dark when the main part of the fibres in the annual rings has a colour darker than sound wood. This is easiest observed on the fibres in a length cut of the log.

Decayed knot (rotten knot). Knot wholly attacked by decay.

Decayed wood. Wood attacked by fungi so that the original strength properties are changed (reduced). It is distinguished between forest decay only developing in living trees, and storage decay developing in felled wood or dead trees. With top rupture, damaged bark, transportation damage, etc. fungal spores can cause fungal attack. Trees have different capabilities to hinder the growth of the fungi, but as a rule it may be stated that the amount and the chance of fungal attack increases with the size of the damage to the bark or the size of the top-rupture.

Discoloured wood. Wood having a darker colour than the rest due to fungal attack

Sharp crook. A log has a sharp crook when the centreline of the log forms two rather parallel lines laying at some distance from each other.

Double pith. Develops in connection with a clefted growth. Double pith develop into a cleft when the logs has two tops with air in between. Top rupture (spike knot) in the end of a log is not defined as double pith.

Double spiral. A log has a double spiral (crook) when the centreline of the log forms a curve in more than one plane.

Dry matter. What is left of the wood when all water is removed. The dry matter is constituted by approximately 99 % organic matter and 1 % ash.

Dry spruce. Spruce tree dried standing.

Dry weight (oven dry weight). Weight of the wood in an absolutely dry condition.

Dry-wood. Area in an otherwise sound log having dried because of damage in the surface/cambium.

Factorial tables SWVM. Table for the judgement of solid wood percentage in a SWVM graded and scaled load/lot. Factors influencing the solid wood percentage are judged according to a predetermined system.

Firm decay. Decayed wood which when compressed by a hard tool in an unfrozen state exhibits the same resistance as surrounding sound wood.

Forest decay. Develops often in the center of the trunk. In the first stages of development the decay is firm, by further development it changes to soft decay.

Goosedecay. Decay in conifers, especially pine. The decay usually has a rather limited spread in the trunk and may often be seen as brown dust in knots on pine.

Grading and scaling duty. Regulation in § 16 in The Forestry Law of 21 May 1965 on the responsibilities of the parts that all forestry products being felled for processing, sales or export are to be graded and scaled.

Gross volume. Log volume including bark and rejects.

Heartwood. The inner part of the stem where the cells are no longer transporting water.Heartwood often has a darker colour than the sapwood (pine and oak). The heartwood of spruce has the same colour as the sapwood.

Knot burr. Old knot or damage, wholly or partly overgrown by the wood and seen as a bump or rounded protrusion on the stem.

Knot cluster. A cluster of three or more visible branches growing out from the same height of the pith of the tree.

Knot tear-out. Crater i log surface by a knot, due to mechanical pruning. Occurs when some of the wood of the knot is torn out instead of being cut in the plane of the surface of the log.

Length direction. The length direction of a log corresponds to a straight line through the centres in both top end butt end of the log.

Length. The shortest distance between the top end and the butt end. With oblique cutting length is measured as the shortest distance between the two end surfaces. The length of a bundle is regarded as volumeweighted average length.

Light decay. Decay is regarded as light when the main part of the fibres in the annual rings have the colour of sound wood. This is easiest observed on the fibres in a length cut of the log.

Log stain (deep sapstain). Wood attacked by a blue stain fungusdiscolouring the wood but not to an extent appreciably reducing the strength properties of the wood. If the discoloration is found only in the outer 5 mm it is named surface sapstain.