Grading and scaling regulations for

Pulpwood

Sanctioned by the board of Norsk Virkesmåling
01.11.2005.
Effective 01.01.2006.

Grading and scaling regulations for pulpwood
1. Conditions for grading and scaling.
  1.1 Grading and scaling obligations.
  1.2 Conditions for grading and scaling.
  1.3 Documentation and labelling.
  1.4 Reception control.
  1.5 Documentation of grading and scaling results.

2. Control and deviation limits.
  2.1 Internal control of SWVM – grading and scaling.
  2.2 Control of method.
    2.2.1 Size of test collectives.
    2.2.2 Taking of test samples.
    2.2.3 Test sampling procedure.
      2.2.3.1 General.
      2.2.3.2 Loose/solid grading and scaling of sawlogs.
      2.2.3.3 Loose/solid grading and scaling of pulpwood.
    2.2.4 Calculation of control results.
    2.2.5 Results of method controls.
  2.3 Regulatory control.
  2.4 Required control.
    2.4.1 Conditions.
    2.4.2 Eventual changes in ordinary grading-scaling and charging of cost of controls.
  2.5 Goal and deviation limits.

3. Requirements for pulpwood.
  3.1 Tolerance table for pulpwood.
  3.2 Quality requirements.
    3.2.1 Wood species.
    3.2.2 Freshness.
    3.2.3 Knots and well pruned.
    3.2.4 Contamination.
    3.2.5 Broken-off ends.
    3.2.6 Length.
    3.2.7 Diameter.
    3.2.8 Forest decay.
    3.2.9 Storage decay.
    3.2.10 Tree died standing.
    3.2.11 Buttresses.
    3.2.12 Cleft.
    3.2.13 Crook.

4. Measuring methods.
  4.1 Log grading and scaling.
    4.1.1 Generally - Log grading and scaling.
    4.1.2 Measuring of length.
    4.1.3 Measuring of diameter.
    4.1.4 Mid-diameter volume.
  4.2 SWVM-grading and scaling.
    4.2.1 Generally - SWVM-grading and scaling.
    4.2.2 Measuring of loose volume.
    4.2.3 Estimation of solid wood volume percentage.
    4.2.4 SWVM-Solid wood volume measurement.
  4.3 Weight-grading and scaling.
    4.3.1 Generally – weight-grading and scaling.
    4.3.2 Green weight.
    4.3.3 Dry-weight and its measurement.
    4.3.4 Determination of weight.
  4.4. Test sampling-grading and scaling.
    4.4.1 Generally – test samling-grading and scaling.
    4.4.2 Measuring accuracy required.
    4.4.3 Test sampling procedure.
    4.4.4 Accomplishment.

1. Conditions for grading and scaling.

1.1. Grading and scaling obligations.
The Law on forestry and forest protection (The Forestry-Law) of 27th of May 2005 has in §8, last link, the following regulation:

«Provided not otherwise specified by the Department buyer and seller of forestry products shall ensure that all roundwood being felled for processing, sale or export is graded and scaled. The Department may give more detailed regulations about registration and documentation obligations regarding such grading and scaling.»

The Department of Agriculture laid 12 June 1995 down regulations stating that:

«Special-timbers, sawlogs, pulpwood and other types of roundwood, including wood graded and measured in standing trees - regardless of species - are to be regarded as forestry products.”

«Buyers and sellers of forestry products are obliged to have all forestry products harvested for processing, sale or export, graded and scaled in a satisfactory manner...”

The Department may give dispensation from the regulation.

1.2. Conditions for grading and scaling.
The conditions at the grading place must be conveniently arranged so that grading and scaling can be performed in an efficient and correct manner and with neutrality regarding part interests. The need for adequate lighting, secure transport arrangements, enough space, solid foundation, etc. must be adequately taken care of. The grading place must furthermore have enough room for the timber grading association to perform control measurements, included herein to be able to store control-objects when needed. When grading at the industry site or at a terminal adequate room must be available to dispose of eventual rejected loads.

With reference to and based on the regulations mentioned, a Timber Grading Association may deny the partners grading and scaling.

Forestry products to be graded and scaled must be properly inspected.

Whether the object to be graded is a truckload, a bundle or a rank, the wood quality is to be determined on the basis of the visible part of the object. The quality of the whole object is determined by the quality of the visible part, if it may be presumed that the latter is representative.

The grader may determine that an object is to be spread out for closer inspection. In such a case the grader decides the measuring method to be used.

1.3 Documentation and labelling.
The grading association stipulates the documentation and supplier identification necessary for roundwood to be graded and scaled. Where the wood to be graded may be mixed with wood belonging to another buyer it may be labelled according to rules laid down by the grading association.

1.4. Reception control.
Prior to grading and scaling the grader judges the load/lot with regard to the following:

• that adequate documentation is provided and that the load/lot is furnished with supplier identification.


• that the roundwood is displayed for grading and scaling so that it may be inspected and judged properly and seems to satisfy the demands in the tolerance table.

If these conditions are not satisfied as judged by the reception control, the load/lot may be rejected for grading and scaling. The parts are to be summoned according to agreed routines.

The grading association conducts reception control on roundwood graded as truckloads at the same time as ordinary grading and scaling is performed.

1.5. Documentation of grading and scaling results.
The results of grading and scaling of all objects are to be documented and made available to buyer and supplier/seller. The minimum requirement is information regarding supplier and buyer, assortment, volume and quality, grading and measuring place and date.

The grading association is obliged to keep the documentation for 3 years.

2 Control and deviation limits
The grading association ought to be quality-certified according to NS-EN ISO. The grading association is to control measuring equipment and the practical grading and scaling according to the quality system of the grading association.

2.1 Internal control of SWVM – grading and scaling.
Internal control of SWVM is the graders self-control of his own judgment at SWVM grading and scaling. The measuring objects are chosen randomly. The SWVM- result of the grader is to be compared with the results of the log-grading of same measuring object performed by the same grader.

2.2 Control of method.
The method control is a method to give the parts and the grading association information regarding systematic and random deviations of volume and value for graded roundwood grouped according to measuring methods and assortments. The sellers and the buyers might be present when the method control is fulfilled, provided this is agreed upon on beforehand.

2.2.1 Size of test collectives.
For each measuring collective a control collective is established. The number of test samples in a control collective is to be so large that the average failure on the average number for value and volume does not exceed +/- 1%.

2.2.2 Taking of test samples.
By taking test samples a procedure is to be used which will give all measuring objects the predetermined probability to be chosen. Sampling is to be performed after measuring and registration, ordinarily by th use of PC or HT. If this is not possible test samples may be chosen by means of draw-plates.

2.2.3 Test sampling procedure
2.2.3.1 General.
Control- measurements are to be performed without knowledge of the results of ordinary grading. All control of method is to be performed according to agreed regulations and terms of contract.
Key-diameter of sawlogs is to be manually measured under bark as the average of the largest and smallest diameter.
Key length is the shortest distance between the butt end and the top end of the log.
The quality is judged on the basis of indications in the surface of the log as it was at the time of ordinary grading. The grader may study the quality of the log closer to be able to determine its correctness , f.inst. by the means of a drill, ax or saw.

2.2.3.2 Loose/solid grading and scaling of sawlogs.
The following routine is to be used in the method control. Data of identification and measurements are ordinary registered by means of a hand-terminal. The diameter of each log is to be registered as the average of the largest and smallest diameter (crosswise callipering). The survey is to be so thorough that all criteria of quality are judged. All logs are in principle to be turned.
The data from the hand-terminal are transmitted to the control-data-base. Eventual errors done by the control-grader may only be corrected in the central control-measuring-system. All such corrections of errors are automatically to be recorded in the data-system.

2.2.3.3 Loose/solid grading and scaling of pulpwood.
By loose and solid grading and scaling of pulpwood the same routine as for sawlogs is to be used, with the exception that the diameter is measured horizontally as the log is placed. The quality is judged as the logs lie and turning of the logs is not required.

2.2.4 Calculation of control results.
Spruce, pine and broadleaves are calculated individually.
As the control measure is accomplished a control report showing the results of ordinary measuring and control measures for each control-object is to be prepared. The control-measuring-system is on the same price-base to calculate the value both for ordinary grading and the control-data. NVM stipulates a common price-base for the ordinary main assortments to be used in the control-measuring-system.

2.2.5 Results of method controls.
The grading association is to receive the results of the method-control according to closer regulations by the board. The results of each control-collective are to be expressed in the annual report of the association. On request the members of the grading association being parts in the roundwood-trade are to have access to the results of the method-control. Publishing normally provides that to control-results are statistically valid. If the contrary occurs this is to be distinctly remarked to the receiver.

2.3 Regulatory control.
This is an internal control of the grading society performed by the inspector of the grading association to secure that the persons who perform the method-control are correctly calibrated relative to one another.

2.4 Required control
2.4.1 Conditions.
Buyer and seller may separately or together demand of control-measurement of a graded lot The demand must in writing be forwarded at the latest one week after the result of the grading is available to the complainer or is made available in Virkesinfo in Skog-Data AS. The control measurement may only be executed when the lot is to be identified and has not been mixed with other wood.
The grading association or the parts may decide that control-measurements of lots may be executed before normal grading for wood that ordinarily is transported away or mixed with other wood just after grading. The grader is not to be informed that control was performed prior to the ordinary grading. The control is to be performed as prescribed for method-control, and be executed by the inspector of the grading association.
For deliveries by truck, eventually with trailer, or railroad-car, the whole delivery on the transport-unit by the same assortment-group constitutes the control-unit. Besides the graded lot constitutes the control-unit. Parts of bundle or load do not make any control-unit. The control-measurement is to state volume and value of the control-unit. The wood quality is to be judged as the wood was by the ordinary grading.
Buyer and seller/supplier may be present at the execution of a required control.
Both parts are informed of the result of the calculations of volume and value from the control measurement compared with the result of ordinary grading.

2.4.2 Eventual changes in ordinary grading-scaling and charging of cost of control.
The result of required control-measurement is to be valid for the control-lot if ordinary grading differs from the control-measurement by more than:

• 5% of the volume or the value of calliper-measured wood


• 10% of the volume or value for SWVW-graded wood


• 10% of dry-weight or value for weight-measured wood

By corrected grading the percentage of the deviation is used for the correction.
The result is not changed if the deviation is like or less than the values mentioned. In the last case the one which has demanded the control has to pay a fee according to rules laid down by the board of the grading association. If the grading result is to be changed all costs related to the control will be covered by the grading association.

2.5 Goal and deviation limits
The goal of all loggrading is 0 in value-deviation with accepted oscillations within the deviationlimits.

By deviation limits Deviation- limit-Value in the withstanding table is to be understood. It is provided that the deviations emerge after method-control of a sufficient number of measuring objects not older than the last 12 months and that the results are statistically significant.
If the results of the method-control lie outside the deviation-limits internal measures are to be taken to bring the control-results towards 0. The action includes analysis of the reasons for the measuring deviations and to implement corrective actions. The corrections may be technical (installations) or of human character (grading judgment or training)

If the tabled Action -limit volume and Action-limit Quality are exceeded measures are taken according to the quality-system of the grading association.

3. Requirements for pulpwood.
Pulpwood is roundwood of coniferous and non-coniferous species to be used as a raw material in the pulp and paper industry.

The individual log is to be fit for further processing. Wood is rejected when it does not fulfil the demands of the tolerance limits to be found in the tolerance table. When grading on the site of the industry the rejects falls to the buyer, if nothing else has been agreed in the contract. The volume of rejects falling to the buyer is to be registered.
The grader may investigate the quality of the wood closer. Damages brought upon the wood during the grading and accompanying handling are not to be regarded as defects

3.2 Quality requirements
3.2.1 Wood species
Pulpwood is classified in the following groups of species:

(Spruce) Norway spruce (Picea abies) and other spruce species as agreed.

(Pine) Scots pine (Pinus silvestris) and other pine species as agreed.

Deciduous species either as pure species or in mixture according to agreement

Other spruce species may be included in spruce deliveries according to contract, f.inst.

silver fir or sitka-spruce.

Other coniferous species may be included in pine-deliveries when agreed in contract, f.inst. spruce or larch. Such mixtures are registered as pine. This is not to be mistaken as a delivery of a mixture of species where each species is to be registered individually.

The contract between the parts determines if the delivery is to be in a pure species or in a mixture of species. If the delivery is to be of a pure species, all foreign species are rejected if nothing else has been agreed.

3.2.2 Freshness
The woodcontract or the general terms of delivery ordinary prescribe a demand for freshness. It may often be difficult to judge how long time has elapsed from logging to delivery and whether the demands to this respect are fulfilled. The wood appearance is changing after logging but very differently at different times of years and under differing storage-conditions.

Fresh standing trees have a white and moist layer of phloem. Following logging dryingout starts and the phloem-layer shrinks. After some time the colour of the phloem-layer changes, first from whit to yellow, then to spotwise brown and finally the whole phloem-layer is brown.

In a layer accepted as fresh, logs not fulfilling the demand for freshness may be found. These logs are not to be rejected provided this is not mentioned in the tolerance table.

If doubt about the freshness of the layer arises, the following test may be performed:

1. Two logs from each side of the layer with as much undamaged bark as possible are taken out, these are supposed to be representative for the whole layer regarding freshness. On each of the logs a 50 cm length of the bark is removed on the available surface of the log. The bark is removed in only one spot on each log and at least one meter from the logends.


2. The individual log is judged as fresh when less than 25 % of the area where bark is removed shows brown discolouring. The layer is judged as being fresh when at least three of the four logs investigated are regarded as being fresh.

3.2.3 Knots and well pruned.
Definition of well pruned:

• All branches with a diameter larger than 1 cm are at the outset to be removed. This means that the branches are to be cut so that the branch-stumps are shorter than 1,5 cm. Branches with diameter less than 1 cm are disregarded unless they involve that grading may not be carried out properly measure-technical.


• It as allowed that up to 1/3 of the logs have branch-stumps larger than 1,5 cm and that up to 5 % of the logs have broken off, hanging on, single branches. It is supposed that the pruning is good enough if these demands are fulfilled. If the pruning in the load is inferior to this, the lot is rejected for grading and the parts are to be informed according to routines agreed more particularly.


• Even if the lot is accepted by the grader as generally well pruned, single logs may be so badly pruned that they are unfit for use in production. Handling of the logs and the barking is often made difficult by bad pruning.


• By control-measurement the graders evaluation of the general pruning is accepted with the exception of cases where this judgment is obviously wrong.

• L = length of branch-stump, being in right angle from the surface of the log under bark to outer solid part of the branch-stump.


• A bulge at the root of the knot is regarded as the surface of the log. Broken, hanging-on branch/knot is not to be regarded as part of the length of the branch-stump.


• D = Knot-diameter under bark, measured at right angle to length of the branch and at right angle to length direction of the log.
  
  

The load/lot is before grading to be judged regarding content of soot, fire-damaged wood, plastics, turf, earth, stone or metal. Grading of loads/lots with such content is to be rejected, or treated according to routines agreed more particularly. It is sufficient that for instance soot is found on a single log.

Sand, gravel or the like which is only loosely attached to the log-surface, is not regarded as reason for rejection except in extreme cases. In some cases it may be impossible to view the wood properly measure-technical because of mud and sand and it is then to rejected until the condition has been remedied.

3.2.5 Broken-off ends

In pulpwood single logs with broken-off ends are permitted. By “single logs” are meant up to 5% of the number. The length of logs with broken-off ends is however to be measured from a full cross section. This has value for estimations of both min. and max. lengths.

3.2.6 Length

By falling lengths is meant that the logs may be cut and delivered at any length within the longest and shortest allowable length. By standard lengths is meant that all logs in the delivery have the same length. Allowable over- and under-measures are +/- 10.0 cm both for falling lengths and standard lengths.

3.2.7 Diameter

Least allowable diameter might be measured anywhere on the log and as a rule this is the outer top-end of the log. Diameter is measured crosswise as two measurements at right angles under bark. Largest diameter under bark is measured anywhere on the log  (not as a crosswise measurement).

3.2.8 Forest decay

Light decay is not regarded as a defect in pulpwood.
It may be difficult to distinguish between light and dark decay, especially when a log-end with decay has been lying in the sunlight and has turned pale. Besides may the cut-off woodfibres in the ends give different refractions.

Decay is best seen when the wood surface is moist. The easiest way to judge whether the decay is light or dark is to cut off a disk from the log-end. This disk is cleaved and then the colour of the fibres is judged in the length cut of the log. The decay is regarded as light when the main part of the fibres in the annual rings have approximately the same colour as sound wood. One ought now and then to carry out such tests to support the faculty of judgment.

Aniline coloured wood is not forest decay, but a type of reaction wood occurring as an early stage before the decay attach occurs. The wood is coloured without the original strength being appreciably changed. The colour is grey-violet and often forms a circle outside the center decay.

Aniline coloured wood may be rather dark and it may be difficult to distinguish from wood where the decay attack has progressed further and become dark decay.

Decay through the whole is allowed. The decay area in the logend most attacked is decisive for the quality.

The demands for the forest decay are given as both a percentage of the diameter and as part of the area.
For centric decay it is naturally the percentage of the diameter which is used. Centric decay making up 50 % of the diameter corresponds to 25 % of the area. If the decay is not centric, the decay-area is judged related to the end-area.
( 70 % of the diameter is for practical reasons used as 50 % of the area, even though it mathematically should be 49 %).

3.2.9 Storage decay

Storage decay is not allowed in ordinary pulpwood.

When fresh logs are stored for some time after felling, the end-areas will dry out and the moisture becomes too low for the storage decay to develop. Further inside the log the conditions may however be more favourable for decay-fungi to develop.

For trees having dried out while standing the conditions for storage decay have often been most favourable close to the ground. In such cases the attacks are usually larger at the normal cutting area at the butt than further up in the log.

For assortments allowing storage decay the demands are valid anywhere on the log.
If the logs have been stored some time and have white “stripes” on the outside of the bark, this is an indication of the logs being greatly attacked by storage decay. In such cases the wood should always be studied more closely. Even without the white “stripes” the log may be attacked. Wood having been lying over a summer is often more or less attacked by storage decay.

In contrast to forest decay, the storage decay may always develop further after felling. The supply of moisture and heat is decisive and the demands regarding storage decay are at the outset strict.
Where the parts have negotiated diverging demands the grader must be observant on the demands to the sum of forest decay and storage decay. Normally this sum may not exceed the demands to forest decay, accordingly 50 % of the area.

3.2.10 Tree died standing

Wood is defined as dry when the tree has died standing. Besides see the point on freshness.

3.2.11 Buttresses

The grading and scaling regulations state that each log may be suitable for production. Logs with buttresses larger than 20 cm are not fit for use in a production-line. Such logs are to be registered and treated as rejects.

Buttresses are to be measured like shown in the drawing. Buttresses are not to be higher than 20 cm measured in relation to the log surface 20 cm further in on the log. Several buttresses around the log are allowed. The log is registered with code 904 logging damage of pulpwood.

The diameter of the smallest ”stem”  has to be at least 1/3 of the log diameter innermost in the cleft and it must be ”air” between the log-parts. If the distance between the log-parts exceeds 3 cm, the knot regulations are to be used.

Forked wood is graded as one log when it is forked above the middle. Logs being forked at the measuring point (air between the log-parts ) is graded like two logs assuming that the shortest end is more than 1,5 m long.

Crook is accepted if the log may be pulled through an imaginary cylinder as long as the log and diameter like the largest diameter of the log   plus 30 cm. The largest diameter is measured at least 25 cm from the butt-end with that it follows that no consideration is taken regarding the diameter closer to the butt-end of the log.  This regulation is in force regardless of type of crook

4. Measuring methods
4.1 Log grading and scaling.

4.1.1 Generally - Log grading and scaling.
Logs are rejected when they do not fulfil agreed demands. The single log is registered in the agreed wood species and quality classes.

4.1.2 Measuring of length.
Length is the shortest distance between the top end and the butt end without consideration taken of the felling-cut.



For pulpwood it is stated that an ordinary felling-cut is included in the length. For the felling-cut to be defined as ordinary the oblique cutting is not to go more than 1/3 of the diameter into the end-surface or up the stem. 

Felling-cut:



In pulpwood single logs with broken-off ends are allowed. By “single logs” is meant up to 5 % of the number of logs. When the wood on both truck and trailer comes from the same supplier the percentage is judged collectively.

Lengths are registrated in 1 dm, 5 dm (half meter) or in fixed lengths according to contract.
1 dm and fixed lengths are always registrated with reduction to the lower length unit. Lengths registrated in 5 dm units are rounded up and down to the nearest length unit.

By length-units in 5 dm the grader have to take into consideration eventually trendy crosscutting, so that the average length for the whole lot is correct. This statement come to practical use by log grading and scaling meaning that lengths have to be rounded up and down in the manner that the volume-weighted average length is correct. If log grading and scaling is registrated in dm, the average will be correct.

4.1.3 Measuring of diameter.
By log-grading is used a calliper. Diameter is to be measured crosswise at a right angle to the length direction.

The diameter is normally measured outside the bark. The grader deducts approximately for bark so that the registered diameter is under bark. The grader is regularly to control his judgment by measuring the bark thickness.

The diameter is to be measured at the middle of the log. If the diameter at the middle for some reason is abnormal, for instance because of a ring of knots, the diameter is to be measured as the average of the diameter on both sides where it is to be regarded as normal.

For butt-logs to be graded as mid-measured pulpwood the callipering point is to be moved 40 cm closer to the butt end. This goes also for wood in standard-lengths. The calliper point is however not be moved for logs being shorter than 2.90 m.

The reasons for this are root-buttresses, which on average may give an under-volume of approximately 5 % when the diameter is measured at the middle.

Calliper point for butt logs:

Middle of the log.

Pulpwood is often laid out so densely that crosswise callipering in practice is impossible. It is the responsibility of the grader to perform the callipering in such a manner that the log diameters are measured as correctly as possible. By grading of particularly oval or large logs (D>25 cm), it is recommended that the callipering in the necessary extent is performed as crosswise callipering.
The diameter is registered in whole cms with reduction to the bottom of the diameterclass. The volume of the single log is calculated on the basis of the class-middle.

The volume is calculated according to this formula:

V=3,14*(D_m+0,5)²*L*1/400

where V is the volume in whole dm³, Dm is the class-bottom of the middle diameter in cm, and L is length in dm. Pi is to be used with two decimals (3,14).

4.2     SWVM-grading and scaling.
4.2.1 Generally - SWVM-grading and scaling.
The wood is to be displayed or stacked in well organised and separate measuring units/lots.
The lot to be measured ought to be the size of a truckbundle. The grading association may grade and scale larger units, provided that control grading and scaling may be executed in a special proper way. If the width of the unit exceeds 3 m, it should be measured in sections. Average figures for the whole load are calculated afterwards.
Logs not fulfilling the requirements of the agreed assortments are rejected and the volume is recorded in dm3. When the wood on both truck and trailer comes from the same supplier, the lot is regarded as a whole. When the wood on truck and trailer comes from two or more suppliers, the reject amount from each supplier is judged separately.

As a main rule only half of the reject volume in a load/lot is on an average visible at the outer edges of the load. This varies much and depends on the reject reasons to be found in the load. Forest decay and logs with too large diameter are the easiest to judge. To compensate for not visible rejects the following table of factors is to be used:

- When both ends of the bundle is to be inspected:

• All visible reject volume due to forest decay and too large diameter is multiplied with 1,5.


• Remaining reject volume is multiplied by 3.

• All visible reject volume due to too large diameter is multiplied with 1,5.


• Remaining reject volume is multiplied by 3.

4.2.2 Measuring of loose volume.

Possible test sampling procedures may be:

1. Counting with test sample measuring. The number of units in the collective is counted. A random sample of units is graded and scaled. The result of the collective is given by the average of these registrations multiplied with the number of units.


2. L/S-grading and scaling (Loose/solid grading and scaling)
   The loose volumes of all units are registered. For a random number of units the solid volume as well as quality is registered. The proportion of loose volume to solid volume for the test samples forms the basis for computation of the volume of the collective. The proportion of loose volume to value (quality distribution) for the test samples is used as a basis for calculation of the value of the collective.


3. C/L/S grading and scaling (Counting/Loose/Solid). All units in the collective are counted. The loose volumes of a random sample of these are graded and scaled while the solid volumes of a random sample within these are graded and scaled. The proportion of loose volume to solid volume and value for the units of which solid volumes are measured forms the basis for the calculation of the value of the whole collective. The calculations are based on all units having the same loose volume as the average of the random number of units of which the loose volumes are measured.


4. SWVM grading and scaling combined with log grading and scaling. All units are SWVM scaled. A random number of units is log graded and scaled to give the basis for calculation of solid wood volume and quality distribution. The proportion between the volume and the quality distribution according to the log grading and scaling and the SWVM grading and scaling is used as a correction factor.

The collective may include one or more suppliers, and one or more buyers. When several suppliers take part in L/F collective, a reduction is to be made in the loose volume for bad stacking, bad pruning, crook, snow, ice and the like. The loose volume shall after measurement contain approximately the same useful volume as average wood. Likewise rejects are to be subtracted when several suppliers participate. At the test sampling-grading rejected logs are not to be part of the loose volume of the load.

If the collective comprises only one supplier, deduction may be omitted by the loose-volume measurement. Similar arrangements like described up front may be utilized also at other test grading arrangements. The least delivery to participate in a collective is one measuring unit.