1、BRITISH STANDARD BS QC 410400: 1992 IEC393-3: 1992 Harmonized system of quality assessment for electronic components Potentiometers for use in electronic equipment Sectional specification for rotary precision potentiometersBSQC410400:1992 This British Standard, having been prepared under the directi
2、onof the Electronic Components Standards PolicyCommittee, was publishedunder the authorityofthe Standards Boardand comes into effect on 15 July 1992 BSI09-1999 The following BSI references relate to the work on this standard: Committee reference ECL/4 Draft announced in BSI News April 1992 ISBN 0 58
3、0 21000 6 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Electronic Components Standards Policy Committee (ECL/-) to Technical Committee ECL/4, upon which the following bodies were represented: EEA (the Association of the Electronics, T
4、elecommunications and Business Equipment Industries) Electronic Components Industry Federation Ministry of Defence National Supervising Inspectorate The following bodies were also represented in the drafting of the standard, through subcommittees and panels: BEAMA Ltd. ERA Technology Ltd. Amendments
5、 issued since publication Amd. No. Date CommentsBSQC410400:1992 BSI 09-1999 i Contents Page Committees responsible Inside front cover National foreword ii Section 1. General 1 General 1 1.1 Scope 1 1.2 Object 1 1.3 Related documents 1 1.4 Information to be given in a detail specification 1 1.5 Marki
6、ng 3 Section 2. Preferred ratings, characteristics and test severities 2 Preferred ratings, characteristics and test severities 4 2.1 Preferred characteristics 4 2.2 Preferred values of ratings 6 2.3 Preferred test severities 8 Section 3. Quality assessment procedures 3 Quality assessment procedures
7、 9 3.1 Structurally similar components 9 3.2 Qualification approval 9 3.3 Quality conformance inspection 22 3.4 Delayed delivery 22 3.5 Apparatus for measuring mechanical accuracy 23 Table I 5 Table II 6 Table III Test schedule for Qualification approval 10 Table IVA 23 Table IVB 23 List of referenc
8、es Inside back coverBSQC410400:1992 ii BSI 09-1999 National foreword This British Standard has been prepared under the direction of the Electronic Components Standards Policy Committee. It is identical with IEC393-3:1992 (QC410400) Potentiometers for use in electronic equipment Part3: Sectional spec
9、ification: Rotary precision potentiometers, published by the International Electrotechnical Commission (IEC) and is a harmonized specification within the IECQ system of quality assessment for electronic components. The standard is to be used in conjunction with BS QC410000:1990 Harmonized system of
10、quality assessment for electronic components: potentiometers for use in electronic equipment. The Technical Committee has reviewed the provisions of IEC410 and QC001001 to which reference is made in the text and has decided that they are acceptable for use in conjunction with this standard. The Brit
11、ish Standard which implements the IECQ Rules of Procedure is BS9000General requirements for a system for electronic components of assessedquality Part3:1991 Specification for the national implementation oftheIECQsystem. A British Standard does not purport to include all the necessary provisions of a
12、 contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Cross-references International Standard Corresponding British Standard IEC63:1963 BS2488:1966 Schedule of preferred numbe
13、rs for the resistance of resistors and the capacitance of capacitors for telecommunication equipment (Technically equivalent) IEC68 BS2011 Environmental testing (All Parts identical or technically equivalent) IEC393-1:1988 BS QC410000:1990 Harmonized system of quality assessment for electronic compo
14、nents: potentiometers for use in electronic equipment (Identical) QC001002:1986 BS QC001002:1991 Rules of Procedure of the IEC Quality Assessment System for Electronic Components (IECQ) (Identical) Summary of pages This document comprises a front cover, an inside front cover, pagesi andii, pages1 to
15、24, an inside back 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.BSQC410400:1992 BSI 09-1999 1 Section 1. General 1 General 1.1 Scope This standard is appli
16、cable to rotary precision potentiometers. These potentiometers are primarily intended for use in electronic equipment. 1.2 Object The object of this standard is to prescribe preferred ratings and characteristics and to select from IEC Publication393-1, appropriate Quality Assessment procedures, test
17、s and measuring methods and to give general performance requirements for this type of potentiometer. Test severities and requirements prescribed in detail specifications referring to this sectional specification shall be of equal or higher performance level, lower performance levels are not permitte
18、d. 1.3 Related documents IEC Publications: NOTEThe above references apply to the current editions except for IEC Publication68, for which the referenced edition in the applicable test clauses of the generic specification shall be used. 1.4 Information to be given in a detail specification Detail spe
19、cifications shall be derived from the relevant blank detail specification. Detail specifications shall not specify requirements inferior to those of the generic, sectional or blank detail specification. When more severe requirements are included, they shall be listed in Sub-clause1.9 of the detail s
20、pecification and indicated in the test-schedules, for example by an asterisk. NOTEThe information given in Sub-clauses1.4.1 and1.4.3 may, for convenience, be presented in tabular form. The following information shall be given in each detail specification and the values quoted shall preferably be sel
21、ected from those given in the appropriate clause of this sectional specification. Publication63:1963 Preferred Number Series for Resistors and Capacitors. Amendment No.1(1967) Amendment No.2(1977) Publication68 Basic Environmental Testing Procedures. Publication393-1:1988 Potentiometers for Use in E
22、lectronic Equipment. Part1: Generic Specification. Publication410:1973 Sampling Plans and Procedures for Inspection by Attributes. Publication QC001001:1986 Basic Rules of the IEC Quality Assessment System for Electronic Component (IECQ). Publication QC001002:1986 Rules of Procedure of the IEC Quali
23、ty Assessment System for Electronic Components (IECQ).BSQC410400:1992 2 BSI 09-1999 1.4.1 Outline drawing and dimensions The detail specification shall incorporate an illustration of the potentiometer being specified. Where space is insufficient to show the detail dimensions required for inspection
24、purposes, such dimensions shall appear on a drawing forming an appendix to the detail specification. The drawing shall give the following details: the dimensions of the spindle and bush. These may be given either on the outline drawing or by reference to IEC Publication915; any locating devices; the
25、 total mechanical travel; the effective electrical travel; the angle of ineffective mechanical travel; the dimensions and the location of terminations; the dimensions which shall be measured in accordance with4.4.2 of IEC Publication393-1; any other dimensional information which will adequately desc
26、ribe the potentiometer. All dimensions shall preferably be stated in mm, however when the original dimensions are given in inches, the converted metric dimensions in mm shall be added. When the potentiometer is not designed for use on printed boards, this shall be clearly indicated in the detail spe
27、cification. 1.4.2 Mounting The detail specification shall specify the method of mounting to be applied for the voltage proof and the insulation resistance tests and for the application of the vibration and bump or shock tests. The potentiometers shall be mounted by their normal means, but the design
28、 may be such that special mounting fixtures are required. In this case the detail specification shall describe the mounting fixtures and they shall be used for the voltage proof and the insulation resistance tests and for the application of the vibration and bump or shock tests. For the latter tests
29、 the mounting shall be such that there shall be no parasitic vibration. 1.4.3 Style (IEC Publication393-1, Sub-clause2.2.3) The style shall be presented by a double-letter code e.g.AB, which is arbitrarily chosen for each detail specification. The style designation, therefore, has no meaning unless
30、the number of the detail specification is also given. 1.4.4 Resistance law See Sub-clause2.1.5.BSQC410400:1992 BSI 09-1999 3 1.4.5 Ratings and characteristics The ratings and characteristics shall be in accordance with the relevant clauses of this specification together with the following: 1.4.5.1 R
31、ated resistance range See Sub-clause2.2.1 The preferred values are those of the E-series of IEC Publication63. NOTEWhen products approved to the detail specification have different ranges, the following statement should be added: “The range of values available in each style is given in the Qualified
32、 Products List”. 1.4.5.2 Bump and shock The bump and shock tests are considered to be alternatives. The detail specification shall indicate which test has been selected. 1.4.6 Marking The detail specification shall specify the content of the marking on the potentiometer and on the package. Deviation
33、s from Sub-clause1.5 of this sectional specification shall be specifically stated. 1.4.7 Ordering information The detail specification shall indicate that the following information, in clear or in coded form, is required when ordering: 1) Rated resistance and tolerance on rated resistance. 2) Resist
34、ance law (if other than linear) and degree of conformity. 3) Number and issue reference of the detail specification and style reference. 4) Spindle and bush dimensions, if not implicit in the style reference. 1.4.8 Additional information (not for inspection purposes) The detail specification may inc
35、lude information (which is not required to be verified by the inspection procedure), such as circuit diagrams, curves, drawings and notes needed for the clarification of the detailspecification. 1.5 Marking 1.5.1 General The information given in the marking is normally selected from the following li
36、st; the relative importance of each item is indicated by its position in the list: a) rated resistance; b) tolerance on rated resistance; c) resistance law (if other than linear) and degree of conformity; d) detail specification and style reference; e) year and month (or week) of manufacture; f) det
37、ails of spindle and bush if not implicit in d) above. This may be in code form; g) manufacturers name and trademark. 1.5.2 The potentiometer shall be clearly marked with a), and b) and c) above and with as many of the remaining items as is practicable. Any duplication of information in the marking o
38、f the potentiometer should be avoided. 1.5.3 The package containing the potentiometer(s) shall be clearly marked with all the information listed above. 1.5.4 Any additional marking shall be so applied that no confusion can arise.BSQC410400:1992 4 BSI 09-1999 Section 2. Preferred ratings, characteris
39、tics and test severities 2 Preferred ratings, characteristics and test severities 2.1 Preferred characteristics The values given in the detail specification shall preferably be selected from the following: 2.1.1 Preferred climatic categories The potentiometers covered by this specification are class
40、ified into climatic categories according to the general rules given in IEC Publication68-1. The lower and upper category temperature and the duration of the damp heat, steady state test shall be chosen from the following: Duration of the damp heat, steady state test:4,10,21 and56 days. The severitie
41、s for the cold and dry heat tests are the lower and upper category temperatures respectively. Because of the construction of some potentiometers these temperatures will occur between two of the preferred temperatures given in IEC Publication68-2. In this case the nearest preferred temperature within
42、 the actual temperature range of the potentiometer shall be chosen for this severity. 2.1.2 Temperature coefficients and temperature characteristics of resistance The limits of change in resistance for the temperature characteristic of resistance test are given in Table I. Each line in table gives t
43、he preferred temperature coefficient and corresponding temperature characteristic for20 C to70 C and limits of change in resistance for the measurement of the temperature characteristics of resistance (see IEC Publication393-1, Sub-clause4.14) on the basis of the category temperature ranges of Sub-c
44、lause2.1.1 of this sectional specification. Different portions of the resistance range may be covered by different temperature characteristics (orcoefficients) of resistance although they appear in a single detail specification. If measurements at additional temperatures are required, they shall be
45、specified in the detail specification. Lower category temperature: 65 C, 55 C, 40 C, 25 C and 10 C. Upper category temperature: + 70 C,+ 85 C,+ 100 C and+ 125 C.BS QC 410400:1992 BSI 09-1999 5 Table I Temperature coefficient Temperature characteristic20/70 C Temperature characteristic of resistance
46、(limits of percentage change in resistance) Reference temperature/Lower category temperature Reference temperature/Upper category temperature 10 6 / C % + 20/65 +20/55 +20/40 +20/25 +20/10 +20/+85 a +20/+100 +20/+125 1000 500 250 150 100 50 25 10 5 2,5 1,25 0,75 0,5 0,25 0,125 0,05 8,5 4,3 2,15 1,3
47、0,85 0,43 0,215 0,085 7,5 3,75 1,88 1,15 0,75 0,375 0,188 0,075 6 3 1,5 0,9 0,6 0,3 0,15 0,06 4,5 2,25 1,13 0,68 0,45 0,23 0,113 0,045 3 1,5 0,75 0,45 0,3 0,15 0,075 0,03 6,5 3,25 1,62 0,98 0,65 0,325 0,162 0,065 8 4 2 1,2 0,8 0,4 0,2 0,08 10,5 5,25 2,62 1,6 1,05 0,525 0,262 0,105 a Potentiometers h
48、aving an upper category temperature of+85 C need not be measured between20 C and70 C.BSQC410400:1992 6 BSI 09-1999 2.1.3 Limits for change in resistance or output ratio The preferred combinations of limits for change in resistance or output ratio in each of the tests listed in the heading of the fol
49、lowing table are as indicated in the lines of the table. NOTEThe clause numbers in the heading of the table refer to IEC Publication393-1. Table II 2.1.4 Limits for insulation resistance The preferred limits for insulation resistance shall be1G7 minimum or, after humidity tests,100M7. 2.1.5 Limits for resistance law The measuring points and associated values of the
