EN 14081-4:2005+A4:2008

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Holzbauwerke - Nach Festigkeit sortiertes Bauholz für tragende Zwecke mit rechteckigem Querschnitt - Teil 4: Maschinelle Sortierung - Einstellungen von Sortiermaschinen für maschinenkontrollierte SystemeStructures en bois - Bois de structure de section rectangulaire classé selon la résistance - Partie 4: Classement par machine - Réglages pour les systèmes de contrôle par machineTimber structures - Strength graded structural timber with rectangular cross section - Part 4: Machine grading - Grading machine settings for machine controlled systems91.080.20Lesene konstrukcijeTimber structures79.040Les, hlodovina in žagan lesWood, sawlogs and sawn timberICS:Ta slovenski standard je istoveten z:EN 14081-4:2005+A4:2008SIST EN 14081-4:2005+A4:2009en,fr,de01-april-2009SIST EN 14081-4:2005+A4:2009SLOVENSKI
STANDARD
EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 14081-4:2005+A4
December 2008 ICS 79.120.10; 79.040 Supersedes EN 14081-4:2005+A3:2008 English Version
Timber structures - Strength graded structural timber with rectangular cross section - Part 4: Machine grading - Grading machine settings for machine controlled systems
Structures en bois - Bois de structure de section rectangulaire classé selon la résistance - Partie 4: Classement par machine - Réglages pour les systèmesde contrôle par machine
Holzbauwerke - Nach Festigkeit sortiertes Bauholz für tragende Zwecke mit rechteckigem Querschnitt - Teil 4: Maschinelle Sortierung - Einstellungen von Sortiermaschinen für maschinenkontrollierte Systeme This European Standard was approved by CEN on 26 August 2005 and includes Amendment 1 approved by CEN on 28 December 2006, Amendment 2 approved by CEN on 13 August 2007, Amendment 3 approved by CEN on 7 February 2008 and Amendment 4 approved by CEN on 20 November 2008.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN Management Centre or to any CEN member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36
B-1050 Brussels © 2008 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 14081-4:2008+A4:2008: ESIST EN 14081-4:2005+A4:2009

! ", # $, % & and ' (. Other parts of this European Standard are EN 14081-1, Timber structures — Strength graded structural timber with rectangular cross section —
Part 1: General requirements EN 14081-2, Timber structures — Strength graded structural timber with rectangular cross section —
Part 2: Machine Grading - Additional requirements for initial type testing EN 14081-3, Timber structures — Strength graded structural timber with rectangular cross section —
Part 3: Machine Grading — Additional requirements for factory production control According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EN 14081-2:2005 and the following apply. 3.1
Speed range maximum and minimum throughput speeds appropriate to the critical speed for the derived settings (see 6.2.2 of EN 14081-2:2005). 4 Symbols a deflection (in mm) b width of timber cross section (in mm)
F force (units as stated) I indicating property (units as stated) P pressure (units as stated) t thickness of timber cross section (in mm) Et,mean characteristic mean tensile modulus of elasticity parallel to grain (in N/mm2)
ft,k characteristic tensile strength (in N/mm2)
ρk characteristic value of density (in kg/m3) SIST EN 14081-4:2005+A4:2009

subscripts
n for setting being calculated a actual size measured as the average dimension of a batch 5 Settings for timber strength grading machines %Tables 1 to 11& give settings for certain grades, timber species and types of grading machine. Settings for other grades, species or grading machines shall be added when the relevant information is sent to, and assessed by, CEN/TC 124.
Picea abies Picea sitchensis 35 ≤ tn ≤ 75 60 ≤ bn ≤ 300 C24 C16 2,68 2,27 Requirements for grading: - Air temperature between + 10 °C and + 35 °C; - Relative humidity in the air ≤ 85 %; - Timber temperature ≥ - 10 °C; - Timber mean moisture content > 10 %; - Maximum feed speed: 150 m/min.
The following equations shall be used to calculate settings for the target size bn × tn. (NOTE
For timber with a thickness to tolerance class 1, i.e. sawn, tn in the following equations is the target tn + 1 mm.)
an = 830,7 tn-1,299
(mm)
Pn = 4,412 Fn / tn0,61
(bar)
()572739,413n1.701nnn+=ttFbF
(kN) C16 1,24 Pine
Pinus nigra Pinus sylvestris 35 ≤ tn ≤ 75 60 ≤ bn ≤ 300 C24 C16 2,79 1,91 C16 1,34 Chile CL Radiata pine Pinus radiata 35 ≤ tn ≤ 50 60 ≤ bn ≤ 300 C27 C16 3,03 1,43 C24 C16 2,32 2,09 C16 0,92 a
See 7.3 in EN 14081-1:2005. b
Timber sizes shall be according to EN 336. c
Grades prefixed by C are strength classes given in EN 338. SIST EN 14081-4:2005+A4:2009

ƒmod Comments and adjustments for size Estonia Finland Latvia Norway Russia d Sweden Poland
Finland Norway Sweden Latvia EE FI LV NO RU SE PL
FI NO SE LV Spruce Picea abies
Pine Pinus
sylvestris 30 ≤ tn ≤ 75 60 ≤ bn ≤ 300 C18 20,8 Requirements for grading: - Air temperature between + 10 °C and + 35 °C; - Relative humidity in the air ≤ 85 %; - Timber temperature ≥ - 10 °C; - Timber mean moisture content > 10 %; - Maximum feed speed: 150 m/min.
The following equations shall be used to calculate settings for the target size bn × tn. (NOTE
For timber with a thickness to tolerance class 1, i.e. sawn, tn in the following equations is the target tn + 1 mm.)
Pn = 4,412 Fn / tn0,61
(bar)
Fn = (5,5I n n bntn3)10-12
(kN)
an = 830,7 tn-1,299
I n = 79.0mod24,022,0f4228nnbt C24 20,8 C27 21,8 C30 28,5 C35 C24 46,5 20,0 C40 C30 C18 54,5 30,6 23,8 a
See 7.3 in EN 14081-1:2005. b
Timber sizes shall be according to EN 336. c
Grades prefixed by C are strength classes given in EN 338. d
Settings apply only to timber grown west of the Ural mountain range in Russia.
The following equations shall be used to calculate settings for the target size bn × tn. (NOTE
For timber with a thickness to tolerance class 1, i.e. sawn, tn in the following equations is the target tn + 1 mm.) an = 830,7 tn-1,299 Pn = 4,412 Fn / tn0,61 ()572739,413n1.701nnn+=ttFbF Spain ES Corsican pine Pinus nigra 40 ≤ tn ≤ 70 100 ≤ bn≤ 200 C30 C18 Not relevant as all settings shall be calculated using equations in comments column Requirements for grading: - Air temperature between + 10 °C and 35 °C; - Relative humidity in the air < 85 %; - Timber temperature > - 10 °C; - Timber mean moisture content > 10 %; - Maximum feed speed: 100 m/min.
The following equations shall be used to calculate settings for the target size bn × tn. (NOTE
For timber with a thickness to tolerance class 1, i.e. sawn, tn in the following equations is the target tn + 1 mm.) an = 830,7 tn-1,299 Pn = 4,412 Fn / tn0,61 FnC30 = (96,297 9 – 0,489 321 tn)anbntn3 / (1,318 943 3 × 109) FnC18 = (54,497 9 – 0,489 321 tn)anbntn3 / (1,318 943 3 × 109) a
See 7.3 in EN 14081-1:2005. b
Timber sizes shall be according to EN 336. c
Grades prefixed by C are strength classes given in EN 338. SIST EN 14081-4:2005+A4:2009

sitchensis 35 ≤ tn ≤ 75 60 ≤ bn ≤ 300 C24 C16 6,35 7,49 Requirements for grading: - Relative humidity in the air ≤ 85 %; - Timber temperature ≥ - 10 °C; - Timber mean moisture content > 10 %; - Maximum feed speed: 105 m/min.
The following equations shall be used to calculate settings for the target size bn × tn. (NOTE
For timber with a thickness to tolerance class 1, i.e. sawn, tn in the following equations is the target tn + 1 mm.)
Fn = 0,010 1 bn tn2
(N)
()()91,0109851,07846,000567,071,36nn5nnn+×+=−btttaa
Actual deflection settings are determined from an/0,19 rounded to the nearest whole number. Refer to calibration tables for machine to convert force Fn to pressure setting C16 13,78 Pine Pinus nigra Pinus
sylvestris 35 ≤ tn ≤ 75 60 ≤ bn ≤ 300 C24 C16 6,10 8,90 C16 12,74 Chile CL Radiata pine Pinus radiata 35 ≤ tn ≤ 50 60 ≤ bn ≤ 300 C27 C16 5,62 11,86 C24 C16 7,35 8,13 C16 18,52 a
See 7.3 in EN 14081-1:2005. b
Timber sizes shall be according to EN 336. c
Grades prefixed by C are strength classes given in EN 338. SIST EN 14081-4:2005+A4:2009

The following equations shall be used to calculate settings for the target size bn × tn where bn and tn are target dimensions.
Refer to calibration tables for machine to convert Fn to pressure setting.
20101,0nnntbF⋅⋅=
(N)
⋅⋅−⋅⋅⋅=−mod152,0186,0mod152,0814,014,218063fbtfbtannnnn
(Bits)
Actual deflection setting an shall be rounded to the nearest whole number
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