1、BRITISH STANDARD BS EN 60068-3-7:2002 IEC 60068-3-7:2001 Environmental testing Part 3-7: Supporting documentation and guidance Measurements in temperature chambers for tests A and B (with load) The European Standard EN 60068-3-7:2002 has the status of a British Standard ICS 19.040; 29.020 NO COPYING
2、 WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBS EN 60068-3-7:2002 This British Standard, having been prepared under the direction of the Electrotechnical Sector Policy and Strategy Committee, was published under the authority of the Standards Policy and Strategy Committee on 19 Februa
3、ry 2002 BSI 19 February 2002 ISBN 0 580 39013 6 National foreword This British Standard is the official English language version of EN 60068-3-7:2002. It is identical with IEC 60068-3-7:2001. The UK participation in its preparation was entrusted to Technical Committee GEL/104, Environmental conditio
4、ns, classification and testing, which has the responsibility to: A list of organizations represented on this committee can be obtained on request to its secretary. From 1 January 1997, all IEC publications have the number 60000 added to the old number. For instance, IEC 27-1 has been renumbered as I
5、EC 60027-1. For a period of time during the change over from one numbering system to the other, publications may contain identifiers from both systems. Cross-references The British Standards which implement these international or European publications referred to in this document may be found in the
6、 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 res
7、ponsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and ke
8、ep 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 inside front cover, the EN title page, pages 2 to 11 and a back cover. The BSI copyright date displayed in this document ind
9、icates when the document was last issued. Amendments issued since publication Amd. No. Date CommentsEUROPEAN STANDARD EN 60068-3-7 NORME EUROPENNE EUROPISCHE NORM January 2002 CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches
10、Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B - 1050 Brussels 2002 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No. EN 60068-3-7:2002 E ICS 19.040; 29.020 English version Environmental testing Part 3-
11、7: Supporting documentation and guidance Measurements in temperature chambers for tests A and B (with load) (IEC 60068-3-7:2001) Essais denvironnement Partie 3-7: Documentation daccompagnement et guide Mesures dans les chambres dessai en temprature pour les essais A et B (avec charge) (CEI 60068-3-7
12、:2001) Umweltprfungen Teil 3-7: Untersttzende Dokumentation und Leitfaden Messungen in Temperaturprfkammern fr die Prfungen A und B (mit Prfgut) (IEC 60068-3-7:2001) This European Standard was approved by CENELEC on 2001-12-04. CENELEC members are bound to comply with the CEN/CENELEC Internal Regula
13、tions 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 Central Secretariat or to any CENELEC member. This
14、 European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CENELEC member into its own language and notified to the Central Secretariat has the same status as the official versions. CENELEC members
15、 are the national electrotechnical committees of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.Foreword The text of document 104/211/FDIS, future ed
16、ition 1 of IEC 60068-3-7, prepared by IEC TC 104, Environmental conditions, classification and methods of test, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as EN 60068-3-7 on 2001-12-04. The following dates were fixed: latest date by which the EN has to be implemented
17、at national level by publication of an identical national standard or by endorsement (dop) 2002-09-01 latest date by which the national standards conflicting with the EN have to be withdrawn (dow) 2004-12-01 This European Standard should be read in conjunction with EN 60068-3-5 and EN 60068-3-6. Ann
18、exes designated “normative“ are part of the body of the standard. In this standard, annex ZA is normative. Annex ZA has been added by CENELEC. _ Endorsement notice The text of the International Standard IEC 60068-3-7:2001 was approved by CENELEC as a European Standard without any modification. _ Pag
19、e2 EN6006837:2002 BSI19February200260068-3-7 IEC:2001 3 CONTENTS INTRODUCTION 4 1 Scope 5 2 Normative references. 5 3 Definitions 6 4 Measuring system 7 4.1 Temperature. 7 4.2 Humidity . 7 4.3 Wall emissivity 8 4.4 Air velocity 8 4.5 Recording device 8 5 Determination of temperature performances. 8
20、5.1 Test area environment 8 5.2 Chamber loading. 8 5.3 Installation of temperature sensors 9 6 Test procedures10 6.1 Confirmation methods10 6.2 Routine monitoring methods.10 7 Evaluation criteria .10 8 Information to be given in the performance report10 A Figure 1 Examples of artificial loads. 7 Fig
21、ure 2 Location of wall sensors. 9 Table 1 Test conditions 6 Table 2 Artificial load - Values . 7 Annex ZA (normative) Normative references to international publications with their corresponding European publications .11 Page3 EN6006837:2002 BSI19February200260068-3-7 IEC:2001 4 INTRODUCTION IEC 6006
22、8 contains fundamental information on environmental testing procedures and severities. The expression “environmental conditioning“ or “environmental testing“ covers the natural and artificial environments to which components or equipment may be exposed so that an assessment can be made of their perf
23、ormance under conditions of use, transport and storage to which they may be exposed in practice. Temperature chambers used for “environmental conditioning“ or “environmental testing“ are not described in any publication, although the method of maintaining and measuring temperature and/or humidity ha
24、s great influence on test results. The physical characteristics of temperature chambers can also influence test results. Page4 EN6006837:2002 BSI19February200260068-3-7 IEC:2001 5 ENVIRONMENTAL TESTING Part 3-7: Supporting documentation and guidance Measurements in temperature chambers for tests A a
25、nd B (with load) 1 Scope This part of IEC 60068 provides a uniform and reproducible method of confirming that temperature test chambers conform to the requirements specified in climatic test procedures of IEC 60068-2-1 and IEC 60068-2-2, when loaded with either heat-dissipating or non heat- dissipat
26、ing specimens under conditions which take into account air circulation inside the working space of the chamber. This standard is destined primarily for users when conducting regular chamber performance monitoring. 2 Normative references The following referenced documents are indispensable for the ap
27、plication of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. IEC 60068-2-1, Environmental testing Part 2: Tests Test A: Cold IEC 60068-2-2, Basic environmental testing proce
28、dures Part 2: Tests. Test B: Dry heat IEC 60068-3-1, Basic environmental testing procedures Part 3: Background information Section one: Cold and dry heat tests IEC 60068-3-5, Environmental testing Part 3-5: Supporting documentation and guidance Confirmation of the performance of temperature chambers
29、 IEC 60068-3-6, Environmental testing Part 3-6: Supporting documentation and guidance Confirmation of the performance of temperature/humidity chambers IEC 60584-1, Thermocouples Part 1: Reference tables IEC 60751, Industrial platinum resistance thermometer sensors Page5 EN6006837:2002 BSI19February2
30、00260068-3-7 IEC:2001 6 3 Definitions For the purpose of this part of IEC 60068, the following definitions apply. 3.1 test specification procedure applied to test chambers with or without forced air circulation; suitable for a wide range of chamber sizes NOTE A summary of test conditions in IEC 6006
31、8-2-1 and IEC 60068-2-2 is given in the following table: Table 1 Test conditions Heat-dissipating Change of temperature Temperature range Test None With Sudden Gradual Aa 65 C to +5 C Ab Ad Ba Bb +30 C to +400 C Bc Bd 3.2 confirmation method (procedure 1) specified method of making continuous measur
32、ements in order to establish whether the performance of a test chamber conforms with the requirements detailed in IEC 60068-2-1, test A and/or IEC 60068-2-2, test B 3.3 routine monitoring method (procedure 2) specified method of making measurements, continuously or at intervals, to ensure that the t
33、est chamber performance is being maintained 3.4 test load test specimen that is installed in the test chamber for the confirmation measurements NOTE The test load is defined by geometric dimensions and by thermal properties. 3.5 artificial load test load made in accordance with this standard with di
34、mensions and thermal properties related to the geometric dimensions and thermal capacity of the specimens intended to be tested in the chamber NOTE Table 2 provides values for an artificial load. Page6 EN6006837:2002 BSI19February200260068-3-7 IEC:2001 7 Table 2 Artificial load - Values Dimensions V
35、olume approximately 20 % of working space Heat transmission Approximately 10 kJ/m 2 K Heat radiation emissivity 0,7 Heat dissipation In accordance with appendix C of IEC 60068-2-2 Airflow l h w s h l w s NOTE s = 3 mm stainless steel or 4 mm aluminium (h, l and w should be smaller than the relevant
36、dimensions of the working space). Figure 1 Examples of artificial loads 4 Measuring system The system used for the confirmation and routine monitoring measurements, either built-in or independent of the chamber, should comply with the following requirements. 4.1 Temperature Platinum resistance therm
37、ometers (in accordance with IEC 60751) or thermocouples (in accordance with IEC 60584-1) should be used. 4.1.1 Temperature sensor In a temperature range from 200 C to +200 C the sensor measurement uncertainty should be in accordance with class A of IEC 60751. 4.2 Humidity Required for confirmation o
38、f IEC 60068-2-2 tests only. Place the sensor independent of humidity as near as practical to the centre of the working space. IEC 1551/01 Page7 EN6006837:2002 BSI19February200260068-3-7 IEC:2001 8 Types of humidity monitoring sensors are described in 4.3 of IEC 60068-3-6. 4.2.1 Humidity sensor Senso
39、r measurement uncertainty should not exceed 3 % RH. 4.3 Wall emissivity Emissivity of the chamber enclosure should be in accordance with table IV of appendix J of IEC 60068-3-1. 4.4 Air velocity An airflow sensor should be installed such that the maximum air velocity impinging on the load can be mon
40、itored. 4.4.1 Air velocity sensor The air velocity sensor measurement uncertainty should be compatible with IEC 60068-2 tolerances. 4.4.2 Air velocity sensor response time The air velocity sensor response time should be greater than 5 s to avoid any influence on it by airflow fluctuation. 4.5 Record
41、ing device For confirmation monitoring, data should be recorded at least once a minute. For routine monitoring, data should be recorded every 5 min. The device utilized for recording data from the chamber monitoring sensors should be independent of the chamber control system. 5 Determination of temp
42、erature performances 5.1 Test area environment In accordance with 4.1 of IEC 60068-3-5. 5.2 Chamber loading Provision is made for measurement of test chamber performance with different loading conditions. Test loads: heat-dissipating non heat-dissipating Artificial loads: heat-dissipating non heat-d
43、issipating NOTE However, when testing large, high heat dissipating specimens, it may be desirable to allow the specimen to develop thermal gradients by using free air chambers or those with a low airflow (typically less that 1 m/s). In such cases the chamber may not have a uniform temperature within
44、 the working space and it is necessary to monitor the temperatures of the air entering and exiting the specimen. Page8 EN6006837:2002 BSI19February200260068-3-7 IEC:2001 9 5.2.1 Location of test load The test load should always be located in the enclosure so that it is entirely within the working sp
45、ace. For heat dissipating multiple loads, heating effects should be minimized in accordance with the following subclauses of IEC 60068-2-2: no forced air circulation 29.1.1.2 and 40.1.1.2, forced air circulation 29.1.2.2 and 40.1.2.2. 5.3 Installation of temperature sensors The temperature sensors s
46、hould be protected from heating and cooling sources and from direct heat radiation. In addition, the wall and load sensors should be protected from convection heat transfer from the surrounding air by suitable insulation. 5.3.1 Position of temperature sensors In accordance with IEC 60068-3-5. 5.3.2
47、Position of wall sensors When chamber walls are directly heated and/or cooled, additional sensors located in accordance with figure 2 are necessary. Figure 2 Location of wall sensors 5.3.3 Position of load sensors Test load temperature sensors should be positioned on representative points of the loa
48、d to indicate that temperature stability is reached. IEC 1552/01 Page9 EN6006837:2002 BSI19February200260068-3-7 IEC:2001 10 6 Test procedures 6.1 Confirmation methods Tests should be conducted at temperatures and with loads which are representative of the intended use of the chamber. 6.1.1 Test wit
49、hout load In accordance with IEC 60068-3-5. 6.1.2 Test with load Install and operate the test load. Repeat test sequence as in 6.1.1 above. 6.2 Routine monitoring methods Routine monitoring should be conducted at regular intervals for control purposes. Additional monitoring should be conducted whenever the chamber undergoes
