1、BRITISH STANDARD BS EN 61012:1998 IEC 61012:1990 Incorporating Amendment No. 1 to BS 7422:1991 (renumbers the BS as BS EN 61012:1998) Filters for the measurement of audible sound in the presence of ultrasound The European Standard EN 61012:1998 has the status of a British Standard ICS 17.140.50BSEN6
2、1012:1998 This British Standard, having been prepared under the direction of the Electronic Equipment Standards Policy Committee, was published under the authority of the Standards Board and comes into effect on 28 February 1991 BSI 05-1999 The following BSI references relate to the work on this sta
3、ndard: Committee reference EEL/24 Draft for comment Special announcement in BSI News, January 1991 ISBN 0 580 19393 4 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Electronic Equipment Standards Policy Committee (EEL/-) to Technical Co
4、mmittee EEL/24, upon which the following bodies were represented: British Medical Association British Radio and Electronic Equipment Manufacturers Association British Society of Audiology British Telecommunications plc Confederation of British Industry Department of Health Department of Trade and In
5、dustry (National Physical Laboratory) Health and Safety Executive Institute of Acoustics Institute of Sound and Vibration Research Institution of Electrical Engineers Medical Research Council Ministry of Defence National Health Service Royal Aeronautical Society Royal National Institute for the Deaf
6、 Society of Environmental Engineers Society of Hearing Aid Audiologists Ltd. University of Exeter Coopted members Amendments issued since publication Amd. No. Date Comments 10092 October 1998 Renumbers BS 7422:1991 as BS EN 61012:1998 and introduces new Annex ZABSEN61012:1998 BSI 05-1999 i Contents
7、Page Committees responsible Inside front cover National foreword ii Foreword 2 Introduction 3 1 Scope 3 2 Filter characteristics 3 3 Sensitivity to various environments 3 4 Rating information and instruction manual 4 Annex ZA (normative) Normative references to international publications with their
8、corresponding European publications 6 Table 1 U-weighting characteristic. Relative frequency response and tolerances 4 Table 2 Pole locations for U-weighting 5 Publication(s) referred to Inside back coverBSEN61012:1998 ii BSI 05-1999 National foreword This British Standard is the English language ve
9、rsion of EN61012:1998. It is identical with IEC61012:1990. The UK participation in its preparation was entrusted to Technical Committee EPL/29, formerly Electro-acoustics, which has the responsibility to: aid enquirers to understand the text; present to the responsible international/European committ
10、ee 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 be obtained on request to its secretary. From 1 Januar
11、y1997, all IEC publications have the number60000 added to the old number. For instance, IEC27-1 has been renumbered as IEC60027-1. 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 Attention is
12、 drawn to the fact that CEN and CENELEC Standards normally include an annex which lists normative references to international publications with their corresponding European publications. The British Standards which implement these international or European publications may be found in the BSI Standa
13、rds 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 responsible fo
14、r 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 6, an inside back cover and a back cover. This standa
15、rd 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.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 61012 April 1998 ICS 17.140.50 Descriptors: Electroacoustic equipment, acoustic measuring in
16、struments, sound level meters, acoustic measurement, ultrasonic frequencies, weighing filters, specifications, electrical properties, frequency responses, environments, instrument sensitivity, marking, technical notices English version Filters for the measurement of audible sound in the presence of
17、ultrasound (IEC 61012:1990) Filtres pour la mesure des sons audibles en prsence dultrasons (CEI61012:1990) Filter fr die Messung von hrbarem Schall im Beisen von Ultraschall (IEC61012:1990) This European Standard was approved by CENELEC on1998-04-01. CENELEC members are bound to comply with the CEN/
18、CENELEC Internal Regulations 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 a
19、ny CENELEC member. This 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 ve
20、rsions. CENELEC members are the national electrotechnical committees of Austria, Belgium, CzechRepublic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and UnitedKingdom. CENELEC European Committee for Electro
21、technical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B-1050 Brussels 1998 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No. EN
22、 61012:1998 EEN61012:1998 BSI 05-1999 2 Foreword The text of the International Standard from IEC61012:1990, prepared by IECTC29, Electroacoustics, was submittted to the formal vote and was approved by CENELEC as EN61012 on1998-04-01 without any modification. The following dates were fixed: Annexes d
23、esignated “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 IEC61012:1990 was approved by CENELEC as a European Standard without any modification. latest date by whi
24、ch the EN has to be implemented at national level by publication of an identical national standard or by endorsement (dop) 1999-03-01 latest date by which the national standards conflicting with the EN have to be withdrawn (dow) 1999-03-01IEC 61012:1990 BSI 05-1999 3 Introduction The frequency respo
25、nse characteristics of sound level meters described in IEC651 are not specified above20000Hz. Consequently these instruments are not suitable for measuring the ultrasonic airborne energy emitted, for example, by ultrasonic cleaners, mechanical tools and welders which operate at frequencies above2000
26、0Hz. Moreover, these instruments are also unsuitable for measuring the audio-frequency part of the sound emitted by such equipment, because the ultrasound will give rise to inflated readings if the frequency response of a particular sound level meter happens to extend to the operating frequency of t
27、he ultrasonic equipment. The noise which is usually of interest with ultrasonic equipment arises from audible sounds produced by the ultrasonic process, for example, the cavitation noise which is audible in ultrasonic cleaners. To achieve reproducible measurements of the audible sound with existing
28、sound level meters which comply with IEC651, the practice is to use the A-weighting response in conjunction with a low-pass filter which has a very sharp cut-off above20000Hz. The purpose of this standard is to specify the characteristics of such a low-pass filter. When the filter characteristic is
29、used with the sound level meter A-weighting specified in IEC651, the resulting nominal values of the overall frequency response fall within the scope of Type1 tolerances. Where the measurement of the ultrasonic component frequencies is required, the practice is to measure the unweighted sound pressu
30、re level using a microphone system which is known to have a frequency response extending sufficiently, for example, to at least the operating frequency of the ultrasonic equipment. A narrow band or one-third octave band filter is usually included in the measuring chain. However, this standard is not
31、 concerned with the measurement of such components, nor with any possible hazard from them. 1 Scope This standard specifies the electrical characteristics of a U-weighting filter mainly for use with sound level meters meeting the requirements of IEC651 for the measurement of audible sound in the pre
32、sence of ultrasound. 2 Filter characteristics 2.1 The filter may be a separate accessory unit or built into a conventional sound level meter. 2.2 The frequency characteristic of the filter shall be designated “U-weighting”. Where the filter is combined with the A-weighting characteristic, the overal
33、l response shall be designated “AU-weighting”. The nominal value of the AU-weighting is the sum of the relative frequency responses of the A- and U-weightings, expressed in decibels, as specified in IEC651 and in this standard respectively. At the frequencies25000Hz,31500Hz and40000Hz, the values 50
34、,0dB, 65,4dB and 81,1dB shall be used as nominal values of the AU-weighting. When quoting the weighted sound pressure level, the frequency weighting “U” or “AU”, as the case may be, shall be indicated. 2.3 The frequency response and tolerances of the filter as a separate unit shall be as shown in Ta
35、ble 1. The pole locations to provide the frequency characteristic of this filter are given inTable 2. If the filter is built into, or externally connected to, a sound level meter, the Type1 tolerances given in IEC651, TableV, for the free field response apply. At the frequencies25000Hz,31500Hz and40
36、000Hz, the overall tolerances shall be +3, Z dB. 2.4 If the filter is battery-operated, means shall be provided to check that adequate battery voltages are maintained so that the performance of the filter remains within the specified tolerances. 3 Sensitivity to various environments 3.1 The effects
37、of magnetic and electrostatic fields shall be reduced as far as practical. The filter shall be tested in a magnetic field of strength80A/m(1oersted) at50Hz or at60Hz. The filter shall be oriented in a direction which gives maximum indication and this indication shall be stated either as a voltage me
38、asured at the output terminals of the filter or, where the filter forms part of a sound level measuring system, as a sound level on the indicator. The test frequency shall be stated. 3.2 The temperature range over which the insertion gain or loss of the filter measured at1000Hz is not affected by mo
39、re than0,5dB referred to the value at20C shall be specified by the manufacturer. If the variation in the insertion gain or loss exceeds0,5dB in the temperature range 10C to+50C, correction information shall be specified by the manufacturer. The manufacturer shall indicate the temperature limits whic
40、h may not be exceeded without risk of permanent damage to the filter.IEC 61012:1990 4 BSI 05-1998 3.3 The manufacturer shall state the range of relative humidity over which the filter is intended to operate continuously. The sensitivity shall not change by more than 0,5dB referred to the indication
41、at65% when the relative humidity varies from30% to90%. The test shall be conducted at a temperature of40C at a frequency of1000Hz. 3.4 If the filter is built into or externally connected to a sound level meter the overall effects of magnetic and electrostatic fields, temperature, and humidity shall
42、not exceed the limits specified in the relevant clauses (Type1 instruments) of IEC651. 4 Rating information and instruction manual 4.1 A filter which is constructed as a separate accessory and which complies with this standard shall be marked to show the number of this standard, the name of the manu
43、facturer, the model number and the serial number. Where the filter is built into a sound level meter and combined with the A-weighting characteristic, the switch position shall be marked “AU”. 4.2 Where the filter is constructed as a separate accessory, the following information shall either be mark
44、ed on the filter or be included in an instruction manual: 4.2.1 The model of sound level meters for which the filter meets the requirements, especially those of2.3 and3.4. 4.2.2 The nominal input and output impedances of the filter. 4.2.3 The nominal source and load impedances between which the filt
45、er is designed to operate. 4.2.4 The insertion loss, in decibels, at1000Hz when the filter is connected between the source and load impedances specified in4.2.3. 4.2.5 The maximum input voltage to the filter. 4.3 An instruction manual shall be supplied with the filter; it shall include at least the
46、information listed below: a) The nominal frequency response characteristic specified inTable 1. b) The effect of magnetic fields as tested in accordance with3.1. c) The effects of temperature in accordance with3.2. d) The effects of humidity in accordance with3.3. Table 1 U-weighting characteristic
47、Relativefrequency response and tolerances Nominal frequency a Exact frequency a Relative response Tolerances Hz Hz dB dB 10 12,5 16 20 25 31,5 40 50 63 80 100 125 160 200 250 315 400 500 630 800 1 000 1 250 1 600 2 000 2 500 3 150 4 000 5 000 6 300 8 000 10 000 12 500 16 000 20 000 25 000 31 500 40
48、000 10,00 12,59 15,85 19,95 25,12 31,62 39,81 50,12 63,10 79,43 100,0 125,9 158,5 199,5 251,2 316,2 398,1 501,2 631,0 794,3 1 000 1 259 1 585 1 995 2 512 3 162 3 981 5 012 6 310 7 943 10 000 12 590 15 850 19 950 25 120 31 620 39 810 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2,8 1
49、3,0 25,3 37,6 49,7 61,8 3 3 3 3 2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 3 +3 ; 6 +3 ; 6 +3 ; 10 +3 ; Z a Nominal frequencies are as specified in ISO266. Exact frequencies are given above to four significant figures and are equal to100010 n/10 , where n is a positive or negative integer. The tolerance shall be zero at the reference frequency (see3.7 of IEC651).IEC 61012:1990 BSI 05-1999 5 Table 2 Pole locations for U-weighting Real part Imag
