1、BRITISH STANDARD Environmental testing Part 3 -6: Supporting documentation and guidance -Confirmation of the performance of temperature/humidity chambers The European Standard EN 60068-3-6:2002 has the status of a British Standard ICs 19.040; 19.080 BS EN IEC 60068-3-612002 60068-3-612001 WkN presen
2、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. - A list of organizations represented on this committee can b
3、e 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 IEC 60027-1. For a period oftime during the change over from one numbering system to the other, publications may contain iden
4、tifiers from both systems. Cr oss-r e fer enc e s The British Standards which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” fa
5、cility 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 responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obli
6、gations. 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 indicates when the document was last issued. Amendments issued since publication Amd.No. IDate I Comments O BSI
7、 13 March 2002 ISBN O 580 39062 4 EUROPEAN STANDARD EN 60068-3-6 NORME EUROPENNE EUROPISCHE NORM Januaw 2002 ICs 19.040; 29.020 English version Environmental testing Part 3-6: Supporting documentation and guidance - Confirmation of the performance of tem perat ure/hu mi d i ty cham bers (IEC 60068-3
8、-612001) Essais denviron nement Partie 3-6: Documentation daccompagnement et guide - Co n f i r m a t i o n d es pe ro r m a n ces des chambres dessais en temprature et humidit (CE1 60068-3-612001) Umweltprfungen Teil 3-6: Untersttzende Dokumentation und Leitfaden - Besttigung des Leistungvermgens v
9、on Tem perat u r-/KI i m a prf kam m ern (i EC 60068-3-612001) This European Standard was approved by CENELEC on 2001-12-04. CENELEC members are bound to comply with the CENKENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard
10、 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 European Standard exists in three official versions (English, French, German). A version in any other l
11、anguage 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 are the national electrotechnical committees of Austria, Belgium, Czech Republic, Denmark, Finland, Fra
12、nce, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Nor
13、mung Central Secretariat: rue de Stassart 35, B - 1050 Brussels O 2002 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No. EN 60068-3-6:2002 E Page 2 EN 60068-3-62002 Foreword The text of document 104/21O/FDIS, future edition 1 of IEC 60
14、068-3-6, 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 60068-3-6 on 2001-12-04. The following dates were fixed: - latest date by which the EN has to be implemented at national lev
15、el by publication of an identical national standard or by endorsement - latest date by which the national standards conflicting with the EN have to be withdrawn (dop) 2002-09-01 (dow) 2004-12-01 This European Standard should be read in conjunction with EN 60068-3-5 and EN 60068-3-7. Annexes designat
16、ed “normative“ are part of the body of the standard. In this standard, annex ZA is normative. Annex ZA has been added by CENELEC. Endorsement not i ce The text of the International Standard IEC 60068-3-6:2001 was approved by CENELEC as a European Standard without any modification. O 13 March 2002 Pa
17、ge 3 EN 60068-3-62002 CONTENTS INTRODUCTION 4 . 5 Scope . Norm at ive references . . 5 Definitions 6 Measuring of performances . 4.1 Test area environment 4.2 Temperature measurement system 7 4.3 Humidity measurement system . 7 4.4 Installation of sensors. Determination of humidity performance . 5.1
18、 Temperature . Standard hum id ity sequence Evaluation criteria . Information to be given in the performance test report 7 7 8 . 8 8 . 8 IO IO Figure 1 - Example of climatogram . 9 Table 1 - Example of test sequence . 9 O 13 March 2002 Page 4 EN 60068-3-62002 INTRODUCTION IEC 60068 contains fundamen
19、tal information on environmental testing procedures and severities. T h e ex press i o n “envi ro n m e n t a I con d it i on i n g “ or “e n v i ro n m e n t a I test i n g “ covers t h e n at u r a I a n d artificial environments to which components or equipment may be exposed so that an assessmen
20、t can be made of their performance under conditions of use, transport and storage to which they may be exposed in practice. Temperature/humidity chambers used for “environmental conditioning“ or “environmental testing“ are not described in any publication, although the method of maintaining and meas
21、uring temperature and/or humidity has a great influence on test results. The physical characteristics of temperature/humidity chambers can also influence test results. O 13 March 2002 Page 5 EN 60068-3-62002 ENVIRONMENTAL TESTING - Part 3-6: Supporting documentation and guidance - Confirmation of th
22、e performance of temperature/humidity chambers 1 Scope This part of IEC 60068 provides a uniform and reproducible method of confirming that temperature and humidity test chambers without load conform to the requirements, specified in climatic test procedures contained in IEC 60068-2 and is destined
23、for users when conducting regular chamber performance monitoring. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced docum
24、ent (including any amendments) applies. IEC 60068-3-4, Environmenfal fesfing - Parf 3-4: Supporfing documenfafion and guidance - Damp heaf fesfs IEC 60068-3-5, Environmenfal fesfing - Parf 3-5: Supporfing documenfafion and guidance - Confirmafion of fhe performance of femperafure chambers IEC 60068-
25、3-7, Environmenfal fesfing - Parf 3-7: Supporfing documenfafion and guidance - Measuremenfs in femperafure chambers for fesf A and fesf B (wifh load) IEC 60584-1, Thermocouples - Parf 1: Reference fables I EC 60751 , Indusfrial plafinum resisfance, fhermomefer sensors IS0 10012-1, Qualify assurance
26、requiremenfs for measuring equipmenf - Parf 1: Mefrological confirmafion sysfem for measuring equipmenf IS0 10012-2, Qualify assurance for measuring equipmenf - Parf 2: Guidelines for confrol of measuremenf processes IS0 4677-1, Afmospheres for condifioning and fesfing - Deferminafion of relafive hu
27、midify - Parf 1: Aspirafed psychromefer mefhod IS0 (unnumbered), Guide fo fhe Expression of Uncerfainfy in Measuremenf O 13 March 2002 Page 6 EN 60068-3-62002 3 Definitions For the purpose of this part of IEC 60068, the following definitions apply. For definitions regarding temperature testing, refe
28、r to IEC 60068-3-5. NOTE Unless otherwise specified humidity is relative humidity (RH) 3.1 temperature/humidity chamber enclosure or space in some parts of which the temperature/humidity conditions specified in IEC 60068-2 can be achieved 3.2 generati on of hum id i ty see clause 3 of IEC 60068-3-4
29、3.3 absolute humidity mass of water vapour present in a unit volume of moist air NOTE Typical units of measure are g/m3. 3.4 dewpoint, fd temperature at which the partial pressure of the water vapour in the air is equal to the saturation vapour pressure over water or ice 3.5 saturation vapour pressu
30、re when a given volume of air, at a constant temperature, has water present and is incapable of holding any more water it is said to be saturated 3.6 partial vapour pressure contribution of water vapour, in a given volume of air, at a constant temperature to the pressure exerted by the atmosphere 3.
31、7 relative hum id i ty (RH) ratio of the partial vapour pressure, divided by the saturation vapour pressure of a given volume of air at a constant temperature, expressed as percentage NOTE The most popular method to express the water vapour content in air is relative humidity. 3.8 temperature/humidi
32、ty stabilization temperature/humidity in the chamber can be considered stable when all points in the working space have reached and have maintained the setpoint temperature/humidity within a given tolerance 3.9 achieved humidity humidity in the chamber at any point within the working space after sta
33、bilization 3.10 climatogram graphic display of combined temperature with relative humidity NOTE See figure 1. O 13 March 2002 Page 7 EN 60068-3-62002 3.11 relative humidity fluctuation fluctuation calculated with the temperature sensor which has the largest fluctuation 3.12 relative hum id i ty grad
34、ient gradient whose predominant contribution is caused by the temperature gradient in the working space NOTE The absolute humidity of the air can be considered to be the same throughout the working space 4 Measuring of performances When performing an assessment of a temperature/humidity chamber a hu
35、midity measuring system, which is independent of the chambers control system should be used. 4.1 Test area environment In accordance with IEC 60068-3-5 4.2 Temperature measurement system The uncertainty of measurement of the output of the measurement system should be determined by calibration of the
36、 system, traceable to international standards (see IS0 10012-1 and IS0 10012-2). 4.3 Humidity measurement system The measurement system should have a calibration at the test conditions, traceable to international standards (see IS0 10012-1 and IS0 10012-2) and the overall measurement uncertainty sho
37、uld be established using the guide to the expression of uncertainty in measurement. Some examples of humidity measurement systems include, but are not limited to, those listed below. 4.3.1 This method (see IS0 4677-1) uses the cooling effect of water evaporation from a wet sock. The temperature of t
38、he sock is measured with a temperature sensor whilst simultaneously measuring the temperature of the air with a second temperature sensor. Wet and dry bulb method 4.3.2 Dewpoint mirror method This method cools the surface of the mirror until condensation occurs on it. The temperature indicated is th
39、e dewpoint temperature. 4.3.3 Lithium chloride sensor This method gives absolute humidity values (dewpoint temperature). 4.3.4 Capacitive sensor Permeation of humidity changes the dielectric properties of certain materials and this is used for direct measurement of relative humidity. O 13 March 2002
40、 Page 8 EN 60068-3-62002 4.4 Installation of sensors 4.4.1 Temperature sensors Normally sensors should be either the resistance type (in accordance with IEC 60751) or the thermocouple type (in accordance with IEC 60584-1). The 50 % response time in air of the sensor shall be between 10 s and 40 s. T
41、he response time of the overall system should be less than 40 s. In a temperature range from -200 “C to +200 “C the sensor measurement uncertainty should be in accordance with class A of IEC 60751. 4.4.2 Humidity sensor A single humidity sensor should be positioned at the centre of the working space
42、. The relative humidity is then calculated at each point in the working space where a temperature sensor is located by using the temperature difference. This assumes that the absolute humidity remains the same throughout the working space. For confirmation monitoring, data should be recorded at leas
43、t once a minute. The device utilised for recording data from the chamber monitoring sensors should be independent of the chamber control system. Sensor measurement uncertainty should not exceed I3 % RH 5 Determination of humidity performance 5.1 Temperature If the chamber is also to be used for dry
44、temperature testing it will be necessary to determine the temperature profile of the working space in accordance with IEC 60068-3-5 before determining the humidity performance. 6 Standard humidity sequence The following test sequence is recommended to obtain the necessary data for confirming the ran
45、ge of operation of a temperature/humidity chamber. For chambers required to continuously test at set temperature/humidity conditions, a single value ver if cat ion wi I I suffice. Test area conditions should be in accordance with 4.1 of IEC 60068-3-5. An example of a test sequence is as follows: O 1
46、3 March 2002 Page 9 EN 60068-3-62002 1 2 Table 1 - Example of test sequence 23 50 Start 23 UP tdP(min.) I Step I Temperature Humidity Remarks “C I %RH 3 4 t3(m i n .) u3 lSBN 92-67-10188-9 EN/HD EN 60068-3-4 EN 60068-3-5 EN 60068-3-7 EN 60584-1 EN 60751 EN 30012-1 Year 2002 ) 2002 ) 2002 ) 1995 ) 19
47、95 ) 1993 ) Undated reference. 2) Valid edition at date of issue. O 13 March 2002 BS EN IEC 60068-3 -6 12002 60068-3-612001 BSI 389 Chiswick High Road Lon don w4 4AL BSI is the independent national body responsible for preparing British Standards. It presents the UK view on standards in Europe and a
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