1、BRITISH STANDARD Round and sawn timber - Determination of the batch volume of sawn timber The European Standard EN 1312 : 1997 has the status of a British Standard ICs 79.040 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW BS EN 1312 : 1997 STD-BSI BS EN 1312-ENGL 1777 1b24bb9
2、 Ob392b3 380 Amd.No. Date BS EN 1312 : 1997 Text affected Committees responsible for this British Standard The preparation of this British Standard was entrusted by Technical Committee BM, Round and sawn timber, to Subcommittee B/543/2, Sawn timber, upon which the foowing bodies were represented Bri
3、tish Iimber Merchants Association British Woodworung Federation Department of the Environment (Building Research Establishment) Iimber Packaging and Pailet Confederation Iimber Research and Development Association Iimber li-ade Federation United Kingdom Softwood Sawmillers Association This British S
4、tandard, having been prepared under the direction of the Sector Board for Building and Civil Engineering, was published under the authority of the Standards Board and comes into effect on 15 September 1997 O BSI 1997 The following BSI references relate to the work on this standard Committee referenc
5、e B/543/2 Draft for comment 9Wl900 DC ISBN O 580 2746 5 I I I I STD-BSI BS EN L3LZ-ENGL 1977 Lb24bb9 Ob372bli 217 BS EN 1312 : 1997 Contents Committees responsible page Inside front cover National foreword ii Foreword 2 Text of EN 1312 3 O BSI 1997 1 STD*BSI BS EN L312-ENGL 1797 Lb24bbS Ob392b5 153
6、BS EN 1312 : 1997 National foreword This British Standard has been prepared by Subcommittee B/543E and is the English hguage version of EN 1312 : 1997 Round and sawn timber - Determination of Uze batch volume of sawn timber, published by the European Committee for Standardizhon (CEN). No existing Br
7、itish Standard is superseded. Cross-references Publication referred to Corresponding British Standard EN 844-3 EN 975-1 BS EN 844 Round and sawn timber - Tmimlogy Part 3 : 1995 Geneml temzs relating to sawn timber BS EN 975 Sawn timber- Appeumnce grading of hardwoods Part 1 : 1996 O - regularized gr
8、een timber, - regulanzed dried timber, - prepared timber, - planed imber, regardless of whether or not the timber meets the requirements of any dimensional or quaitative standards. 2 Normative references This European Standard incorporates, by dated or undated reference, provisions is the width, in
9、metres, to three decimal places; is the length, in metres, to three decimal places. Batches consisting of similar pieces are measured on the basis of the volume of a reference piece. If the volume of this piece is calculated as a separate operation, it shall be expressed in m3 to four decimal places
10、. The volume of a piece, measured separately, is expressed in m3 to three decimal places. 4.4 Calculation of the volume of a batch The volume of a batch shall be expressed in m3 to three decimal places. 4.4.1 Batches of timber, all pieces of the same size The volume is given by the formula: where V=
11、n x v, n V, is the number of pieces in the batch; is the volume of the reference piece. O BSI 1997 STD-BSI BS EN L3LZ-ENGL 1797 = Lb29bb Ob392b T9 m Page 4 EN 1312 : 1997 4.4.2 Batches of timber, all pieces of equal thickness and width but varying in length Measure the length of each piece individua
12、lly, in order to determine the total aggregate length of the batch. 4.4.3 Batches of timber, all pieces of equal thickness but varying in width and length The widths of equally long pieces are measured individuallx in order to determine their total aggregate width. The calculation may be based on th
13、e total width of a layer of planks, placed edge to edge. For each length, the volume is the aggregate width multiplied by the thickness and the length. 4.4.4 Batches of timber, with varying dimensions (thickness, length or width) It is recommended to split the batch into subbatches containing pieces
14、 of identical size, and then to proceed as above. 4.4.5 Volume of an unedged board, or a batch of separated unedged boards The volume is calculated takjng half the width of any wane into account, ignoring bark, halfway along the length of the board. In case of a feature at this point which would giv
15、e an incorrect result, two measurements are made equidistant from the mid-point and their mean is used. It is the supplier who measures. Sound sapwood is included in the measurement. 4.4.6 Volume of a boule l A A I C jn(/ / C Figure 1. Volume of a boule The total aggregate width is the basis of calc
16、ulation. This total aggregate width, or total width of the whole of the pieces in a boule, or of a series of successive pieces from any one boule, of equal length and thickness, is measured equidistant from the ends, perpendicular to the axis, ignoring bark. It is equal to the sum of the widths of t
17、he top faces of each unedged board. If the widths of the top faces of each unedged board are referred to as AA, BB, CC, DD, EE, , MM, then the developed width, Z b, is shown by the following formula: Z b =AA + BB + CC+ DD+EE+ . + MM 6 Reduction for defects and insect or fungal damage (separated uned
18、ged boards and boules) In accordance with the grade definitions laid down in EN 975-1, prEN 1611-1 and prEN 1611-2, volume reductions may be carried out where certain features or damage are present in the boards constituting the batch. One or more boards may not be withdrawn from a boule of a given
19、grade on the grounds that they contain a defect or that they are unsound. In such a case, volume reduction is carried out so as to take into account only the part which is: - sound, i.e. nondeteriorat Fax: 0181 996 7400. BSI offers members an individual updathg service called PLUS which ensures that
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