1、BRITISH STANDARD BS EN 60068-2-70: 1996 IEC 68-2-70: 1995 Environmental testing Part 2: Tests Test Xb: Abrasion of markings and letterings caused by rubbing of fingers and hands The European Standard EN60068-2-70:1996 has the status of a British Standard This Part should be read in conjunction with
2、BS EN60068-1:1995 General andguidance ICS 19.040BSEN60068-2-70:1996 This British Standard, having been prepared under the direction of the Electrotechnical Sector Board, was published under the authority of the Standards Board and comes into effect on 15 September 1996 BSI 11-1998 The following BSI
3、references relate to the work on this standard: Committee reference GEL/50 Draft for comment 92/05519 DC ISBN 0 580 26159 X Committees responsible for this British Standard The preparation of this British Standard was entrusted to Technical Committee GEL/50, Environmental testing of electrotechnical
4、 products, upon which the following bodies were represented: Federation of the Electronics Industry GAMBICA (BEAMA Ltd.) Ministry of Defence Society of Motor Manufacturers and Traders Limited Amendments issued since publication Amd. No. Date CommentsBS EN 60068-2-70:1996 BSI 11-1998 i Contents Page
5、Committees responsible Inside front cover National foreword ii Foreword 2 Text of EN 60068-2-70 3 List of references Inside back coverBSEN60068-2-70:1996 ii BSI 11-1998 National foreword This British Standard has been prepared by Technical Committee GEL/50 and is the English language version of EN60
6、068-2-70:1996 Environmental testing Part2:Tests Test Xb: Abrasion of markings and letterings caused by rubbing of fingers and hands published by the European Committee for Electrotechnical Standardization (CENELEC). It is identical with IEC 68-2-70:1995 published by the International Electrotechnica
7、l Commission (IEC). Cross-reference Publication referred to Corresponding British Standard EN 60068-1:1994 BS EN 60068 Environmental testing (IEC 68-1:1988 1) ) BS EN60068-1:1995 2)General and guidance A British Standard does not purport to include all the necessary provisions of a contract. Users o
8、f British Standards are responsible 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, pages i and ii, theEN title page, pages 2 to 8, an inside ba
9、ck cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. 1) Undated in the text. 2) BS EN60068-1:1995 includes the corrigendum October 1988 and A1:1993 to IEC 68-1
10、.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 60068-2-70 January 1996 ICS 19.040 Descriptors: Environmental testing, abrasion of marking, abrasion of letterings, rubbing of fingers and hands, test apparatus, test fabric, test liquid English version Environmental testing Part 2: Tests Test Xb
11、: Abrasion of markings and letterings caused by rubbing of fingers and hands (IEC 68-2-70:1995) Essais denvironnement Partie 2: Essais Essai Xb: Effacement des marquages et inscriptions par friction des doigts et des mains (CEI 68-2-70:1995) Umweltprfungen Teil 2: Prfungen Prfung Xb: Prfung der Best
12、ndigkeit von Kennzeichnungen und Aufschriften gegen Abrieb, verursacht durch Wischen mit Fingern und Hnden (IEC 68-2-70:1995) This European Standard was approved by CENELEC on 1995-11-28. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for
13、 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 European Standard exists in three offic
14、ial 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 are the national electrotechnical commi
15、ttees of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Eur
16、opisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B-1050 Brussels 1996 Copyright reserved to CENELEC members Ref. No. EN60068-2-70:1996 EEN60068-2-70:1996 BSI 11-1998 2 Foreword The text of document 50/359/DIS, future edition 1 of IEC 68-2-70, prepared by TC 50,
17、Environmental testing, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as EN60068-2-70 on 1995-11-28. The following dates were fixed: Annexes designated “normative” are part of the body of the standard. Annexes designated “informative” are given for information only. In th
18、is standard, annex ZA is normative and annex A is informative. Annex ZA has been added by CENELEC. Contents Page Introduction 3 1 Scope 3 2 Normative reference 3 3 General description 3 4 Description of the test apparatus 3 4.1 Test apparatus 3 4.2 Test fabric 4 4.3 Test liquids 4 5 Severity 4 6 Pre
19、conditioning 4 7 Initial measurements 4 8 Testing 4 9 Intermediate measurements 5 10 Recovery 5 11 Final measurements 5 12 Information to be given in the relevant specification 5 Annex A (informative) Schematic drawing of a test apparatus for test Xb 6 Annex ZA (normative) Normative references to in
20、ternational publications with their corresponding European publications 7 Figure1.A Schematic drawing of a test apparatus (clause 4.1) 6 Table 1 3 latest date by which the EN has to be implemented at national level by publication of an identical national standard or by endorsement (dop) 1996-09-01 l
21、atest date by which the national standards conflicting with the EN have to be withdrawn (dow) 1996-09-01EN60068-2-70:1996 BSI 11-1998 3 Introduction This standard describes a method of test applicable to markings and lettering on such parts of electrical products (switches, plugs, handles etc.) whic
22、h in service are subjected to rubbing forces caused by the fingers or other parts of the hand. This standard may be applied to other industrial products. This test should be required by the relevant specification when the stress during normal use is very high or in such cases where the legibility is
23、 important because of safety aspects or other reasons. 1 Scope This International standard provides a standard method to determine the resistance of markings and letterings on flat or curved surfaces against abrasion as may occur for example by manually operating actuators and keyboards. The method
24、is also suitable to test the resistance against fluid contamination as may occur under normal use. 2 Normative reference The following normative document contains provisions which, through reference in this text, constitute provisions of this part of IEC 68. At the time of publication, the edition i
25、ndicated was valid. All normative documents are subject to revision, and parties to agreements based on this part of IEC68 are encouraged to investigate the possibility of applying the most recent editions of the normative document indicated below. Members of IEC and ISO maintain registers of curren
26、tly valid International Standards. IEC 68-1:1988, Environmental testing Part1:General and guidance. Amendment 1 (1992) 3 General description The surface under test shall be repeatedly stressed by the rubbing movement of a test piston. The tip of the test piston due to its elasticity is deformed in s
27、uch a way as to fit the surface under test. The material, hardness and shape of the piston, the movement and the angle of action are chosen in such a way that the pressure and friction executed by a human finger or by the ball of a thumb are simulated. To obtain reproducible conditions of friction a
28、 piece of fabric is placed between the piston and the surface under test (either as a cover of the piston or as a curtain, hanging between piston and surface). Depending on the relevant specification this fabric may either be dry (dry test) or soaked with a specified test liquid if the test is inten
29、ded to cover the influence of fluid contamination as may occur in normal use (wet test). 4 Description of the test apparatus 4.1 Test apparatus An example of a suitable test apparatus is shown in the schematic drawing in annex A. The apparatus moves the rubbing-piston under an angle of 45 5 via a co
30、nnecting rod against the surface under test. The force F (given in the relevant specification) results in an elastic deformation of the test piston combined with a rubbing movement s across the surface under test. The rubbing movement shall be from 1mm to 4mm. The pressing cycle shall be repeated as
31、 many times as prescribed by the relevant specification. For non-rigid test specimens (for example keyboards) the specification shall specify additional requirements (for example fixing). Table 1 Dimensions mm Size A B C 1 20 20 2 2 10 20 1EN60068-2-70:1996 4 BSI 11-1998 The test piston consists of
32、elastic material which shall be inert against the test liquids and shall have a Shore-A-hardness of 47 5 (for example synthetic rubber). The size of the test piston shall be selected fromTable 1 according to the shape and dimension of the test specimen and the kind of lettering. The relevant specifi
33、cation shall prescribe the size of the test piston. If necessary other dimensions for the test piston more suited to the test specimen may be chosen. They shall then be prescribed by the relevant specification. The abrasive dust produced during the test shall not influence the result of the test. Th
34、erefore it shall be removed continuously from the area between the test piston and the test specimen. NOTEThe accumulation of abrasive dust can be avoided by mounting the test surface vertically (the dust will fall down) or by blowing it off by means of compressed air free of oil and any pollution a
35、t room temperature. 4.2 Test fabric Between the test specimen and the test piston there shall be an easily replaceable piece of fabric which also can be a cover for the test piston. The specifications 3)of the test fabric shall be: For the “dry test” the fabric shall be changed or moved such as to b
36、ring an unused part of it into contact with the test specimen after a maximum of10000 cycles in order to avoid wear. For the “wet test” (see4.3) the soaking of the fabric shall be repeated after every 10cycles. Alternatively it may be moved so that a fresh piece of fabric is brought in between the t
37、est piston and the test specimen after every 10cycles. The soaking may be achieved by dipping the fabric into the test liquid or by periodic dripping of the test liquid on to the fabric. At the start of a new test and after a maximum of 10000 cycles the fabric shall be renewed to avoid stray results
38、 due to encrustation and wear. 4.3 Test liquids When a “wet test” is specified in the relevant specification the test liquid(s) shall be specified. Such liquids may be: artificial sweat; lubricating oil; hydraulic oil; other relevant liquid. If more than one test liquid is specified different specim
39、ens shall be used for each liquid unless otherwise specified by the relevant specification. 5 Severity The severity is given by the force with which the test piston acts on the specimen and by the number of cycles. It shall be chosen from the following values. The chosen values shall be prescribed i
40、n the relevant specification. 6 Preconditioning The surface under test shall be in the condition of delivery after normal production. The relevant specification may prescribe preconditioning (for example ageing, dusting, cleaning). 7 Initial measurements The specimen shall be submitted to a visual c
41、heck and if prescribed by the relevant specification to dimensional and functional checks. 8 Testing Unless otherwise specified in the relevant specification the test shall be a “dry test” carried out at standard atmospheric conditions according to IEC68-1. The test specimens are stressed in the tes
42、t apparatus (see clause4.1) with the prescribed severity. The test piston shall be moved with a speed of60mm/s towards the test surface. It is pressed against the surface with the force given for the chosen severity. The test conditions shall be chosen so that the “piston pressing on the surface” an
43、d “piston lifted” times are approximately equal. The time during which the force is applied shall be not less than 0,2s. The cycle frequency shall be (2 0,5) strokes per second. The relevant specification may prescribe other frequencies. NOTEWith higher frequencies it is possible that the temperatur
44、e of the test specimen is unacceptably increased. 3) According to ISO/CD 12947-1, Textiles Determination of abrasion resistance of fabrics Martindale method Part1:Martindale abrasion testing machine. material: wool warp: 175 threads/dm10 threads/dm weft: 135 threads/dm 8 threads/dm weight per area:
45、195g/m 2 Force: 1 N0,2 N; 5N1 N; 10 N2N; 50N10 N; 100N20N. Number of cycles: 10 1 ; 10 2 ; 10 3 ; 10 4 ; 10 5 ; 10 6 ; 10 7 .EN60068-2-70:1996 BSI 11-1998 5 9 Intermediate measurements Intermediate measurements may be required by the relevant specification. 10 Recovery Recovery may be required by th
46、e relevant specification. 11 Final measurements The specimen shall be submitted to a visual check and if prescribed by the relevant specification to dimensional and functional checks. The relevant specification shall provide the criteria upon which the acceptance or rejection of the specimen is to b
47、e based. 12 Information to be given in the relevant specification When this test is included in a relevant specification, the following details shall be given, in so far as they are applicable. The relevant specification shall supply information as required in the clauses listed below, paying partic
48、ular attention to the items marked with an asterisk *as this information is always required. Clause/Subclause a) Dimension of the test piston * 4.1 b) Additional requirements for non-rigid test specimens * 4.1 c) If the test is to be wet * 4.2 d) Test liquid(s) if a wet test is specified * 4.3 e) If
49、 more than one liquid, the number and distribution of test samples 4.3 f) Severities (force and number of cycles) * 5 g) Preconditioning 6 h) Initial measurements * 7 i) Test conditions if not standard atmospheric 8 j) Cycle frequency if not two strokes per second * 8 k) Intermediate measurements * 9 l) Recovery after test 10 m) Final measurements * 11EN 60068-2-70:1996 6 BSI 11-1998 Annex A (informative) Schematic drawing of a test apparatus for test Xb Figure 1.A Schematic drawing of a test apparatus (clause4.1)EN60
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