BS EN 12939-2001 Thermal performance of building materials and products - Determination of thermal resistance by means of guarded hot plate and heat flow meter methods - Thick prod.pdf

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1、BRITISH STANDARD BS EN 12939:2001 Incorporating Corrigendum No. 1 Thermal performance of building materials and products Determination of thermal resistance by means of guarded hot plate and heat flow meter methods Thick products of high and medium thermal resistance The European Standard EN 12939:2

2、001 has the status of a British Standard ICS 91.100.60 BS EN 12939:2001 This British Standard, having been prepared under the direction of the Engineering Sector Policy and Strategy Committee, was published under the authority of the Standards Policy and Strategy Committee on 15 January 2002 BSI 20

3、December 2002 ISBN 0 580 36718 5 National foreword This British Standard is the official English language version of EN 12939:2000. This British Standard together with BS EN 12664:2001 and BS EN 12667:2001 supersedes BS 874-2.1:1986 and BS 874-2.2:1998 which are withdrawn. The UK participation in it

4、s preparation was entrusted by Technical Committee RHE/9, Thermal insulating materials, to Subcommittee RHE/9/2, Thermal properties of insulating materials, which has the responsibility to: A list of organizations represented on this subcommittee can be obtained on request to its secretary. Cross-re

5、ferences The British Standards which implement international or European publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of Brit

6、ish Standards Online. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; presen

7、t to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an in

8、side front cover, the EN title page, pages 2 to 32, an inside back cover and a back cover. The BSI copyright date displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. Date Comments 14030 Corrigendum No. 1 20 December 2002 Addition of su

9、persession details to national forewordEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 12939 November 2000 ICS 91.100.60 English version Thermal performance of building materials and products - Determination of thermal resistance by means of guarded hot plate and heat flow meter methods - Thick

10、 products of high and medium thermal resistance Performance thermique des matriaux et produits pour le btiment - Dtermination de la rsistance thermique par la mthode de la plaque chaude garde et la mthode fluxmtrique - Produits pais de haute et moyenne rsistance thermique Wrmetechnisches Verhalten v

11、on Baustoffen und Bauprodukten - Bestimmung des Wrmedurchlasswiderstandes nach dem Verfahren mit dem Plattengert und dem Wrmestrommessplatten-Gert - Dicke Produkte mit hohem und mittlerem Wrmedurchlasswiderstand This European Standard was approved by CEN on 18 October 2000. CEN members are bound to

12、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 Managem

13、ent 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 Management Centre has the same status as the off

14、icial versions. CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMI

15、T EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: rue de Stassart, 36 B-1050 Brussels 2000 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 12939:2000 EPage 2 EN 12939:2000 Contents Page Foreword 3 Introdu

16、ction 3 1S c o p e 4 2 Normative references 4 3 Definitions, symbols and units 5 4 Instrumentation 6 5 Procedures 7 6 Calculations and test report 13 Annex A (normative) Instrumentation 16 Annex B (normative) Conversion utilities for thick specimens 19 Annex C (informative) Advanced procedures to te

17、st thick specimens exceeding thickness capabilities of the apparatus 23 Annex D (informative) Items which are expected to be specified in product standards 32Page 3 EN 12939:2000 Foreword This European Standard has been prepared by Technical Committee CEN/TC 89 “Thermal performance of buildings and

18、building components“, the secretariat of which is held by SIS. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by May 2001, and conflicting national standards shall be withdrawn at the latest by May

19、2001. This European Standard has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Association, and supports essential requirements of EU Directive(s). According to the CEN/CENELEC Internal Regulations, the national standards organizations of the follo

20、wing countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. The annexes A and B are normative. The ann

21、exes C and D are informative. Introduction This standard is intended to complement EN 12667. It addresses specific problems when testing, according to European product standards, thick high and medium thermal resistance specimens with a heat flow meter or guarded hot plate. In this standard the refe

22、rences to ISO 8301:1991 and ISO 8302:1991 are limited to some experimental procedures and to the error analysis. The guarded hot plate and heat flow meter methods are described in EN 12667; assessment procedures are described in EN 1946-2:1999 and EN 1946-3:1999. A CEN Report CR xxx, The use of inte

23、rpolating equations in relation to measurements on thick specimens, (under preparation) supplies additional information on the use of interpolating functions to predict the thickness effect. Among existing apparatus for steady state thermal testing, guarded hot plate apparatus and heat flow meter ap

24、paratus can be operated up to specimen thicknesses of 100 mm to 150 mm if the accuracy has to be kept within 2 % (and possibly 1 %), while the accuracy of guarded and calibrated hot box apparatus, which can test thicker specimens, is not as good as that of the previously mentioned two test apparatus

25、. As the thickness of many insulating products exceeds 100 mm to 150 mm, there is a need for a testing procedure that will supply enough information to predict the thermal performance of insulation products at their actual thicknesses. Different options are offered in this standard; the most appropr

26、iate one may be indicated in product standards. When the thickness effect is relevant, i.e. when the thermal resistance of a thick product cannot be calculated as the sum of the thermal resistances of slices cut from the product, some material parameters are determined for use in interpolating equat

27、ions. The procedure to determine these parameters is split into preliminary and routine measurements and evaluations, see C.1. Background information and additional information on the use of interpolating equations is to be found in CR xxx.Page 4 EN 12939:2000 1S c o p e This standard gives the proc

28、edures to determine the thermal resistance of products the thicknesses of which exceed the maximum thickness for guarded hot plate or heat flow meter apparatus. In any case most of the procedures described in this standard require apparatus that allows tests on specimens up to 100 mm thick. This sta

29、ndard gives guidelines to assess the relevance of the thickness effect, i.e. to establish whether the thermal resistance of a thick product can or cannot be calculated as the sum of the thermal resistances of slices cut from the product, these guidelines complement the indications given in ISO 8302:

30、1991 on the guarded hot plate apparatus. This standard describes testing conditions which prevent the onset of convection. which could take place in some products under the considered temperature differences and thicknesses. 2 Normative references This standard incorporates by dated or undated refer

31、ence, provisions from other publications. These normative references are cited at the appropriate places in the text and the publications are listed hereafter. For dated references, subsequent amendments to or revisions of any of these publications apply to this standard only when incorporated in it

32、 by amendment or revision. For undated references the latest edition of the publication referred to applies (including amendments). EN 1946-2:1999 Thermal performance of building products and components - Specific criteria for the assessment of laboratories measuring heat transfer properties Part 2:

33、 Measurements by guarded hot plate method EN 1946-3:1999 Thermal performance of building products and components - Specific criteria for the assessment of laboratories measuring heat transfer properties Part 3: Measurements by heat flow meter method EN 12667:- 1)Thermal performance of building mater

34、ials and products - Determination of thermal resistance by means of guarded hot plate and heat flow meter methods - Products of high and medium thermal resistance EN ISO 7345 Thermal insulation - Physical quantities and definitions (ISO 7345:1987) EN ISO 9288 Thermal insulation - Heat transfer by ra

35、diation - Physical quantities and definitions (ISO 9288:1989) ISO 8301:1991 Thermal insulation - Determination of steady-state thermal resistance and related properties - Heat flow meter apparatus ISO 8302:1991 Thermal insulation - Determination of steady-state thermal resistance and related propert

36、ies - Guarded hot plate apparatus1To be publishedPage 5 EN 12939:2000 3 Definitions, symbols and units 3.1 Terms and definitions For the purposes of this standard the terms and definitions given in EN ISO 7345 and EN ISO 9288 apply. NOTE EN ISO 9288 defines spectral directional extinction, absorptio

37、n and scattering coefficients and the spectral directional albedo only, while this standard makes use of total hemispherical coefficients, which can be obtained by the previous ones by appropriate integrations. 3.2 Symbols and units Symbol Quantity Unit A conduction parameter W/(mK) B solid conducti

38、on parameter m 3 /kg C radiation parameter Wm 2 /(kgK) E extinction parameter for combined conduction and radiation m -1 F complement to unity of the “two flux model“ albedo L thickness effect parameter R thermal resistance m 2 K/W R 0 , R 01 , R 02 extrapolated thermal resistance at zero thickness

39、m 2 K/W T thermodynamic temperature K T transfer factor d/R (of a specimen) W/(mK) Z emissivity parameter d thickness m d b mean bead or grain diameter m d thickness beyond which thermal resistance becomes linear m e edge temperature ratio h r radiative heat transfer surface coefficient W/(m 2 K) q

40、density of heat flow rate W/m 2 q r density of radiative heat flow rate W/m 2 q t total density of heat flow rate W/m 2 t time s * mass extinction parameter m 2 /kgPage 6 EN 12939:2000 Symbol Quantity Unit emissivity thermal conductivity W/(mK) a thermal conductivity of air W/(mK) g thermalconductiv

41、ity of gas W/(mK) r radiativity (of a material) W/(mK) cd combined gaseous and solid thermal conductivity W/(mK) (of a material) t thermal transmissivity (of a material) d/ R W/(mK) Celsius temperature C density kg/m 3 s density of the solid matrix kg/m 3 n Stefan-Boltzmann constant W/(m 2 K 4 ) * t

42、wo-flux model albedo 4 Instrumentation 4.1 General The apparatus used for the measurements shall be a guarded hot plate or heat flow meter conforming with the requirements of EN 12667. This standard gives neither relevant design criteria and proven performance checks nor the determination of apparat

43、us emissivity; these, as well as specific apparatus requirements applicable to the procedures described in this standard, are to be found either in EN 1946-2:1999 or EN 1946-3:1999, according to the apparatus used. Only those apparatus requirements affecting specimen sizes and tolerances are given i

44、n this standard. When it is not explicitly stated otherwise, guarded hot plate apparatus requirements are assumed to be applicable also to heat flow meter apparatus. Some recommended sizes and tolerances are supplied in this standard. In 4.2 and 4.3 requirements for common testing conditions are spe

45、cified. More information is given in annex A. 4.2 Maximum specimen thickness The maximum specimen thickness should be according to EN 12667, see limit values in its table A.1 for some common apparatus sizes. See also annex A of this standard for more information concerning low density specimens.Page

46、 7 EN 12939:2000 4.3 Minimum specimen thickness, flatness tolerances The procedures described in this standard may require measurements at the minimum allowed specimen thickness (which depends upon apparatus parameters and testing conditions). The requirements of A.3.3 of EN 12667 shall be met, exte

47、nding them for a thermal resistance of the specimen as low as 0,3 m 2 K/W. The following two testing conditions shall be considered in relation to this standard for both guarded hot plate and heat flow meter apparatus: a) Tests on non rigid specimens achieving a good contact with the apparatus and w

48、hose thermal resistance is greater than or equal to 0,3 m 2 K/W, e.g. mineral wool boards or elastomeric cellular boards. In this case the departures from a true plane result in an error in the measurement of specimen thickness. This error shall be less than 0,5 % (see table A.1 of EN 12667). For de

49、tailed information see annex A of this standard. b) Tests on rigid specimens having a thermal resistance greater than or equal to 0,3 m 2 K/W, e.g. polystyrene or rigid polyurethane boards. In this case the departures from a true plane are the source of contact resistances; these shall be less than 0,5 % of the specimen thermal resistance (see table A.2 of EN 12667). This standard does not cover special testing techniques (use of cont