1、BRITISH STANDARD BS 6840-17: 1991 IEC 268-17: 1990 (including Corrigendum September 1991) Sound system equipment Part 17: Methods for specifying and measuring the characteristics of standard volume indicators (Implementation of CENELEC HD483.17 S1)BS6840-17:1991 This British Standard, having been pr
2、epared under the directionof the Electronic Equipment Standards Policy Committee, was published underthe authority of the Standards Board and comes intoeffect on 30 April 1991 BSI 07-1999 The following BSI references relate to the work on this standard: Committee reference EEL/32 Draft for comment 8
3、8/26018 DC ISBN 0 580 19533 3 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Electronic Equipment Standards Policy Committee (EEL/-) to Technical Committee EEL/32, upon which the following bodies were represented: Association of British
4、 Theatre Technicians Association for Consumer Research (ACRE) Audio Engineering Society British Educational Equipment Association British Kinematograph, Sound and Television Society British Radio and Electronic Equipment Manufacturers Association British Telecommunications plc Consumer Policy Commit
5、tee of BSI Federation of British Audio Independent Broadcasting Authority Independent Television Association Institution of Electrical Engineers National Council for Educational Technology (NCET) Professional Lighting and Sound Association Radio Electrical and Television Retailers Association Royal
6、Institute of British Architects Royal National Institute for the Deaf Society of Cable Television Engineers Sound and Communication Industries Federation Amendments issued since publication Amd. No. Date Comments 7701 July 1993 Indicated by a sideline in the marginBS6840-17:1991 BSI 07-1999 i Conten
7、ts Page Committees responsible Inside front cover National foreword ii Foreword 2 1 Scope 3 2 Definitions 3 3 Reference indication 3 4 Reference voltage 3 5 Reference volume Characteristics to be specified 3 6 Division of the scale 3 7 Amplitude-frequency response Performance requirement 3 8 Respons
8、e time 3 9 Overswing Performance requirement 3 10 Return time Performance requirement 3 11 Reversibility error Performance requirement 4 12 Input impedance Performance requirement 4 13 Distortion introduced by the standard volume indicator Performance requirement 4 14 Temperature range Performance r
9、equirement 4 15 Overload input level Performance requirement 4 16 Rectifier Performance requirement 4 17 Colour of scale and scale card 4 18 Mounting on panels Presence of magnetic material 4 19 Mounting angle Performance requirement 4 20 Classification of the characteristics to be specified 4 Annex
10、 ZA (normative) Other international publications quoted in this standard with references of the relevant European publication Inside back cover National annex NA (informative) Cross-reference Inside back cover Figure 1 Connection of the standard volume indicator 5 Figure 2 Schematic diagram of the m
11、ethod of measurement of response time of the standard volume indicator 7 Figure 3 Scale of the standard volume indicator 8 Table 1 Attenuator characteristics 3 900 7 constant impendance 6BS6840-17:1991 ii BSI 07-1999 National foreword This Part of BS6840has been prepared under the direction of the E
12、lectronic Equipment Standards Policy Committee and is identical with IEC268-17:1990 Sound system equipment Part17: Standard volume indicators and its corrigendum of September 1991, published by the International Electrotechnical Commission (IEC). This Part of BS6840 implements Harmonization Document
13、 HD483.17S1 published by the European Committee for Electrotechnical Standardization (CENELEC). BS 6840 consists of the following Parts: Part 1: Methods for specifying and measuring general characteristics used for equipment performance; Part 2: Glossary of general terms and calculation methods; Par
14、t 3: Methods for specifying and measuring the characteristics of sound system amplifiers; Part 4: Methods for specifying and measuring the characteristics of microphones; Part 5: Methods for specifying and measuring the characteristics of loudspeakers; Part 6: Methods for specifying and measuring th
15、e characteristics of auxiliary passive elements; Part 7: Methods for specifying and measuring the characteristics of headphones and headsets 1) ; Part 8: Methods for specifying and measuring the characteristics of automatic gain control devices; Part 9: Methods for specifying and measuring the chara
16、cteristics of artificial reverberation, time delay and frequency shift equipment; Part 10: Methods for specifying and measuring the characteristics of peak programme level meters; Part 11: Specification for application of connectors for the interconnection of sound system components; Part 12: Specif
17、ication for applications of connectors for broadcast and similar use; Part 13: Guide for listening tests on loudspeakers; Part 14: Guide for circular and elliptical loudspeakers; outer frame diameters and mounting dimensions; Part 15: Specification for matching values for the interconnection of soun
18、d system components; Part 16: Guide to the “RASTI” method for the objective rating of speech intelligibility in auditoria; Part 17: Methods for specifying and measuring the characteristics of standard volume indicators. A British Standard does not purport to include all the necessary provisions of a
19、 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. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, theHD title page, pages 2
20、to 8, 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. 1) In preparation.HARMONIZATION DOCUMENT DOCUMENT DHARMONISATION HARMONISIERUNGSDOKUMENT
21、 HD 483.17 S1 July 1992 UDC 534.86:621.317.7 Descriptors: Electroacoustic, electroacoustical equipment, indicating device, electroacoustical intensity, characteristics, specifications English version Sound system equipment Part 17: Standard volume indicators (IEC 268-17:1990 + corrigendum 1991) Equi
22、pements pour systmes lectroacoustiques Dix-septime partie: Indicateurs de volume normaliss (CEI 268-17:1990) Elektroakustische Gerte Teil 17: Standard-vu-Meter (IEC 268-17:1990) This Harmonization Document was approved by CENELEC on 1992-06-16. CENELEC members are bound to comply with the CEN/CENELE
23、C Internal Regulations which stipulate the conditions for implementation of this Harmonization Document on a national level. Up-to-date lists and bibliographical references concerning national implementation may be obtained on application to the Central Secretariat or to any CENELEC member. This Har
24、monization Document exists in three official versions (English, French, German). CENELEC members are the national electrotechnical committees of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland
25、 and United Kingdom. CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B-1050 Brussels 1992 Copyright reserved to CENELEC members Ref. No. HD 483.17
26、 S1:1992 EIEC268-17:1990 2 BSI 07-1999 Foreword The CENELEC questionnaire procedure, performed for finding out whether or not the International Standard IEC268-17:1990 and its corrigendum of September1991could be accepted without textual changes, has shown that no common modifications were necessary
27、 for the acceptance as Harmonization Document. The reference document was submitted to the CENELEC members for formal vote and was approved by CENELEC as HD 483.17 S1 on16June1992. The following dates were fixed: For products which have complied with the relevant national standard before1993-06-01,
28、as shown by the manufacturer or by a certification body, this previous standard may continue to apply for production until1998-06-01. Annexes designated “normative” are part of the body of the standard. In this standard, Annex ZA is normative. latest date of announcement of the HD atnational level (
29、doa) 1992-12-01 latest date of publication ofa harmonized national started (dop) 1993-06-01 latest date of withdrawal ofconflicting national standards (dop) 1993-06-01IEC268-17:1990 BSI 07-1999 3 1 Scope This standard gives the characteristics to be specified, performance requirements and the releva
30、nt methods of measurement for electro-mechanical volume indicators. The concept of “volume” is a practical way of assigning a numerical value to the magnitude of electrical speech and music programme signals. Since the response of the meter movement of such an indicator to the rapidly varying progra
31、mme voltage is greatly dependent upon its dynamic characteristics, a standard for volume measurements shall therefore include a specification of these characteristics. The term “vu” (pronounced “vee-you” and written with lower case letters) is used to express volume in terms of vu above or below a s
32、pecified reference level. This standard does not deal with peak programme level meters which are the subject of IEC268-10. 2 Definitions 2.1 “vu” is a quantitative expression of volume in an electrical circuit 2.2 the standard volume indicator is a device for the indication of volume having the char
33、acteristics described in this standard a standard volume indicator (or vu-indicator) consists of three parts: an indicating meter with a full-wave rectifier; an attenuator (adjustable loss); a fixed series resistor (fixed loss). the reading is obtained by the algebraic addition of the value indicate
34、d by the meter and the value indicated on tile attenuator scale 3 Reference indication The reference indication is the meter scale point marked0or100% on the vu scale (seeFigure 3). 4 Reference voltage 4.1 Characteristic to be specified The r.m.s. value of a steady state sinusoidal voltage of1000Hz
35、which results in the reference indication. 4.2 Performance requirement Under conditions that the attenuator is set to zero loss position (marked +4), an applied voltage of1,228 V (+4dB ref.0,775 V) shall provide reference indication. 5 Reference volume Characteristics to be specified The level in de
36、cibels, with respect to a stated reference, of a1000Hz sinusoidal signal which gives a reading of0vu on the scale of the vu meter. NOTEThe “reading of0vu” is the algebraic sum of the meter and attenuator readings. 6 Division of the scale The scale shall be calibrated in vu, with a maximum value of +
37、3vu and a minimum value of 20vu. The point of reference indication (0on the vu scale) shall be located within a sector between2/3and3/4of full scale. In addition to the vu scale, a 0-to-100% scale should be provided with100% corresponding to0vu (seeFigure 3). 7 Amplitude-frequency response Performan
38、ce requirement Over the frequency range of31,5 Hz 16kHz, the deviation of the indication due to a sinusoidal signal of constant voltage, which produces reference indication at1000Hz, shall be less than0,5vu. 8 Response time 8.1 Performance requirement The response time shall be0,3s 10% for the point
39、er to reach99% of the reference indication. 8.2 Method of measurement For the measurement of the response time of the meter pointer, the arrangement shown in Figure 2 should be used. This method employs a1kHz signal adjusted to give the reference indication. The time interval is measured between the
40、 application of this signal and the time at which the pointer reaches99% of reference deflection. 9 Overswing Performance requirement The pointer shall overswing the reference deflection by at least1% and not more than1,5%. 10 Return time Performance requirement The time between the removal of a1000
41、Hz signal giving reference indication and the moment when the pointer reaches its mechanical zero position shall not differ greatly from the response time. NOTEThe expression “differ greatly” is used because the return time can normally not be adjusted independently of the response time.IEC268-17:19
42、90 4 BSI 07-1999 11 Reversibility error Performance requirement The difference in level indication when reversing the polarity of an unsymmetrical signal giving reference indication shall be less than0,2vu. 12 Input impedance Performance requirement The input impedance shall be7,5k7 3%. 13 Distortio
43、n introduced by the standard volume indicator Performance requirement The total harmonic distortion introduced into a source of6007 shall not exceed0,2% for all deflections between 20vu and0vu and for all frequencies between31,5Hz and8kHz. 14 Temperature range Performance requirement The deviation w
44、ith temperature of the level resulting in reference indication shall be less than0,2vu between +10C and +40C, and less than0,5vu between0C and +50C. 15 Overload input level Performance requirement The indicator shall withstand, without damage or any effect on calibration, an overload of ten times th
45、e voltage giving reference indication for a time interval of5s and an overload of three times that voltage for unlimited period of time. 16 Rectifier Performance requirement The volume indicator shall employ a full wave rectifier, with a characteristic such that the scale shown in Figure 3 is produc
46、ed. 17 Colour of scale and scale card The colour of the scale card shall match as closelyaspossible the colour expressed accordingtothe Munsell system of colour identification2,93Y(9,18/4,61) 2) . The Figures0,+1, +2 and +3 and that part of the scale between0and +3 shall be red. The rest of the scal
47、e shall be printed in black. The following reference shall be printed either along the top or bottom edge of the scale card in such a way that it is invisible when the indication meter is viewed directly from the front: IEC 268-17 No marking other than those associated with the scale should be visib
48、le on the scale card when the indication meter is viewed directly from the front. The scale of the standard volume indicator is shown in Figure 3. 18 Mounting on panels Presence of magnetic material The presence of magnetic material near the movement of the instrument may affect its calibration and
49、dynamic characteristics. The instrument should therefore not be mounted on a steel panel. The adverse effect may be deemed negligible if the thickness of the steel panel does not exceed 1,6 mm and the mounting hole diameter is dimensioned to be as large as possible without being visible from the front. 19 Mounting angle Performance requirement The instrument shall be mountable at any angle without affecting its calibration and dynamic characteristics. 2
