BS EN 1946-2-1999 Thermal performance of building products and components - Specific criteria for the assessment of laboratories measuring heat transfer properties - Measurements b.pdf

1、| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BRITISH STANDARD BS EN 1946-2:1999 The Eur

2、opean Standard EN 1946-2:1999 has the status of a British Standard ICS 91.100.01; 91.120.10 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Thermal performance of building products and components Specific criteria for the assessment of laboratories measuring heat transfer prop

3、erties Part 2: Measurements by guarded hot plate methodThis British Standard, having been prepared under the direction of the Engineering Sector Committee , was published under the authority of the Standards Committee and comes into effect on 15 May 1999 BSI 05-1999 ISBN 0 580 32162 2 BS EN 1946-2:1

4、999 Amendments issued since publication Amd. No. Date Text affected National foreword This British Standard is the English language version of EN 1946-2:1999. The UK participation in its preparation was entrusted by Technical Committee RHE/9, Thermal insulating materials, to Subcommittee RHE/9/2, Th

5、ermal properties of insulating materials, which has the responsibility to: aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international

6、 and European developments and promulgate them in the UK. A list of organizations represented on this subcommittee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in t

7、he BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are r

8、esponsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 16, an inside back cover and a back cover.CEN European

9、Committee for Standardization Comite Europe en de Normalisation Europa isches Komitee fu r Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels 1999 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 1946-2:1999 E EUROPEAN

10、 STANDARD EN 1946-2 NORME EUROPE ENNE EUROPA ISCHE NORM January 1999 ICS 91.100.01; 91.120.10 Descriptors: building products, heat transfer, thermal resistance, testing, laboratory assessment, hot plate, error analysis, performance check English version Thermal performance of building products and c

11、omponents Specific criteria for the assessment of laboratories measuring heat transfer properties Part 2: Measurements by guarded hot plate method Performance thermique des produits et composants pour le ba timent Crite res particuliers pour le valuation des laboratoires measurant les proprie te s d

12、e transmission thermique Partie 2: Mesurages selon la me thode de la plaque chaude garde e Wa rmetechnisches Verhalten von Bauprodukten und Bauteilen Technische Kriterien zur Begutachtung von Laboratorien bei der Durchfu hrung der Messungen von Wa rmeu bertragungseigenschaften Teil 2: Messung nach V

13、erfahren mit dem Plattengera t This European Standard was approved by CEN on 13 December 1998. 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-da

14、te lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat 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

15、 responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembour

16、g, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.Page 2 EN 1946-2:1999 BSI 05-1999 Foreword This European Standard has been prepared by Technical Committee CEN/TC 89, Thermal performance of buildings and building components, the Secretariat of which is held by SIS. Thi

17、s 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 July 1999, and conflicting national standards shall be withdrawn at the latest by July 1999 This European Standard is divided into parts. The first par

18、t covers common criteria applicable to all heat transfer property measurements; each subsequent part covers the specific technical criteria applicable to each heat transfer property measurement method described in appropriate standards. The following parts have been developed: Part 1: Common criteri

19、a Part 2: Measurements by guarded hot plate method Part 3: Measurements by heat flow meter method Part 4: Measurements by hot box methods Part 5: Measurements by pipe test methods According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are b

20、ound 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. Contents Page Foreword 2 1 Scope 3 2 Normative references 3 3

21、Definitions 3 4 Equipment manual 3 5 Calibration and maintenance files 8 6 Measurement procedure document 8 7 Assessment 9 Annex A (normative) Determination of apparatus emissitivity 10 Annex B (normative) Edge heat losses and maximum specimen thickness 11 Annex C (informative) Calculations of some

22、guarded hot plate errors 13Page 3 EN 1946-2:1999 BSI 05-1999 1 Scope This part 2 of this standard provides specific technical criteria for the assessment of laboratories to undertake steady-state heat transfer property measurements by the guarded hot plate method according to prEN 12667 and prEN 126

23、64. It complements the common criteria in part 1. Guidance is given on the organization and contents of the equipment manual, the calibration and maintenance files and the measurement procedure document. It provides information on mandatory equipment performance specifications, equipment description

24、 and on calculations for the equipment design and error analysis. It provides information on experimental procedures suitable for the assessment of equipment accuracy. 2 Normative references This standard incorporates by dated or undated reference, provisions from other publications. These normative

25、 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 by amendment or revision. For undated references the lat

26、est edition of the publication referred to applies. EN 1946-1:1999, Thermal performance of building products and components Specific criteria for the assessment of laboratories measuring heat transfer properties Part 1: Common criteria. prEN 12664:1996, Building materials Determination of thermal re

27、sistance by means of guarded hot plate and heat flow meter methods Dry and moist products of medium and low thermal resistance. prEN 12667:1996, Building materials Determination of thermal resistance by means of guarded hot plate and heat flow meter methods Products of high and medium thermal resist

28、ance. prEN 12939, Building materials Determination of thermal resistance by means of guarded hot plate and heat flow meter methods Thick products of high and medium thermal resistance. ISO 8302:1991, Thermal insulation Determination of steady-state thermal resistance and related properties Guarded h

29、ot plate apparatus. 3 Definitions The definitions in EN 1946-1 and in ISO 8302:1991 also apply to this part of the standard. 4 Equipment manual 4.1 General The equipment manual shall provide the information specified in 5.2.2 to 5.2.5 of EN 1946-1:1999 and the information specified in this clause. N

30、OTE Information common to more than one piece of equipment need not be duplicated, e.g. the principle, details of the design and operation of two pieces of equipment built to a common design. Annex B of prEN 12664:1996 or prEN 12667:1996, which indicates all limiting values for apparatus performance

31、 and testing conditions, shall be used as a check-list during the assessment process by the parties concerned to ensure compliance with all the requirements of those standards. 4.2 Equipment performance specifications According to 2.3.1 of ISO 8302:1991, the upper and lower limits for the following

32、relevant tested properties and testing conditions, including possible interactions among them, shall be specified: specimen thickness; thermal resistance; temperature difference across the specimen; heating and cooling unit temperature; surrounding environment (temperature, relative humidity) at the

33、 edge of the specimen during the test. 4.3 Equipment description The following information shall be documented and shall be available for examination during the assessment: principle of operation (see 1.6.1 of ISO 8302:1991); type of apparatus (see 1.6.2.1, 1.6.2.2 and 1.6.4 of ISO 8302:1991); princ

34、ipal dimensions of apparatus, in particular heating unit width, guard width and gap width; simple diagrams illustrating the design of the equipment with special attention to the gap design (see 2.1.1.5 of ISO 8302:1991), the cooling unit piping (see 2.1.2 of ISO 8302:1991) and edge insulation (see 2

35、.1.3 of ISO 8302:1991); position, connections and numbering of temperature sensors (see 2.1.4.1 of ISO 8302:1991); electrical components/instruments, apparatus enclosure and main ancillary equipment; details of data acquisition system and related computer programs for data analysis. To avoid duplica

36、tion, reference can be made to manuals supplied by the instrument manufacturers or to relevant clauses of ISO 8302:1991. 4.4 Equipment design and error analysis 4.4.1 General With reference to the performance specification given in 4.2, details shall be given of the design guidelines followed, and t

37、he error analysis based on 2.2 of ISO 8302:1991, as summarized in 4.4.2 to 4.4.11. Some guidelines on error analysis are given in this subclause; more specific information on some errors is supplied in annex B, while error calculations are supplied in annex C for some typical cases. Examples of equi

38、pment conforming to annex C are supplied in D.2 of prEN 12664:1996 and in D.2 of prEN 12667:1996. For equipment having characteristics exactly as indicated in this subclause or design details as indicated in annex C of this part and in D.2 of prEN 12664:1996 or in D.2 of prEN 12667:1996, no further

39、calculations are needed. In other circumstances similar calculations can be performed by analogy.Page 4 EN 1946-2:1999 BSI 05-1999 Table 1 Minimum and maximum allowed specimen thickness Dimensions in millimetres Overall size Metering section Guard width Maximum thickness (edge limit for e = 0,25) Fl

40、atness tolerance (0,025%) Minimum thickness (flat. tol.) Max. gap Minimum thickness 1) (gap limit) 200 100 50 30 0,05 10,0 1,25 12,5 300 200 50 35 0,08 15,0 2,50 25,0 300 150 75 45 0,08 15,0 1,88 18,8 400 200 100 60 0,10 20,0 2,50 25,0 400 100 150 80 0,10 20,0 1,25 12,5 500 300 100 65 0,13 25,0 3,75

41、 37,5 500 250 125 75 0,13 25,0 3,13 31,3 500 200 150 85 0,13 25,0 2,50 25,0 600 300 150 90 0,15 30,0 3,75 37,5 800 500 150 100 0,20 40,0 6,25 62,5 800 400 200 120 0,20 40,0 5,00 50,0 1000 500 250 150 0,25 50,0 6,25 62,5 1) Thicknesses applicable for gap widths according to the seventh column of Tabl

42、e 1; for thinner gaps see 4.4.3. 4.4.2 Edge heat losses and maximum specimen thickness According to 3.2.1 of ISO 8302:1991, the sum of the imbalance error and edge heat loss error shall be kept within 0,5 %. In a good equipment design, the two errors will be of the same order of magnitude, hence a 0

43、,25 % limit can be suggested for both. Table 1 shows for some apparatus dimensions the maximum allowed specimen thickness according to 2.2.1 of ISO 8302:1991, when there is no edge insulation and when the edge temperature ratio, e, is 0,25; e is defined as (T e 2 T 2 )/(T 1 2 T 2 ), where T 1 and T

44、2 are respectively the temperatures of the hot and cold surfaces of the specimen, and T e is the temperature at the edge of the specimen, assumed to be uniform. EXAMPLE: e = 0,25 corresponds to a temperature of the edge of the specimen 5 K below the mean test temperature, when the temperature differ

45、ence between the hot and cold side of the specimen is 20 K. NOTE The edge heat loss error is zero for homogeneous isotropic specimens when e is close to 0,5; the absolute value of the edge heat loss error increases almost symmetrically when e deviates on either side from 0,5. In the range 0,25# e #

46、0,75, this error is maximum for e = 0,25. Larger specimen thicknesses can be used for some specimens if edge insulation or edge temperature control is used, if auxiliary or gradient guards are installed, or medium and high conductivity specimens are tested. See annex B for additional information. Wh

47、en the maximum specimen thickness to be specified according to 4.2 exceeds the appropriate value given in Table 1, lateral losses shall be calculated. If, according to these calculations, they exceed those permitted by ISO 8302:1991, the performance check data shall be examined and, if no experiment

48、al evidence exists to justify the claimed maximum specimen thickness, the maximum specimen thickness to be specified according to 4.2 shall be reduced. 4.4.3 Maximum gap width and minimum specimen thickness According to 2.1.1.3 of ISO 8302:1991 the gap width, g, shall be such that the gap area is le

49、ss than 5 % of the metering area, i.e. the gap width, g, shall not be greater than 1,25 % of the metering area side, L. The maximum gap width resulting from this requirement is given in the seventh column of Table 1. The minimum specimen thickness, d m , is related to the gap width. d m shall be at least ten times the gap width, see 1.7.6 of ISO 8302:1991. Thus, when the gap width reaches its maximum allowed value according to the above criteria, the minimum specimen thickness shall n