1、BRITISH STANDARDBS EN ISO 4869-3:2007Acoustics Hearing protectors Part 3: Measurement of insertion loss of ear-muff type protectors using an acoustic test fixtureThe European Standard EN ISO 4869-3:2007 has the status of a British StandardICS 13.340.20g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g5
2、6g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58BS EN ISO 4869-3:2007This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 August 2007 BSI 20
3、07ISBN 978 0 580 55989 1National forewordThis British Standard is the UK implementation of EN ISO 4869-3:2007. It supersedes BS EN 24869-3:1994 which is withdrawn. The UK participation in its preparation was entrusted by Technical Committee EH/1, Acoustics, to Subcommittee EH/1/1, Hearing.A list of
4、organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obli
5、gations.Amendments issued since publicationAmd. No. Date CommentsEUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN ISO 4869-3July 2007ICS 13.340.20 Supersedes EN 24869-3:1993 English VersionAcoustics - Hearing protectors - Part 3: Measurement ofinsertion loss of ear-muff type protectors using an aco
6、ustic testfixture (ISO 4869-3:2007)Acoustique - Protecteurs individuels contre le bruit - Partie3: Mesurage de laffaiblissement acoustique desprotecteurs du type serre-tte au moyen dun montagedessai acoustique (ISO 4869-3:2007)Akustik -Gehrschtzer - Teil 3: Messung derSchalldmmung von Kapselgehrscht
7、zern unterVerwendung einer akustischen Prfvorrichtung (ISO 4869-3:2007)This European Standard was approved by CEN on 30 June 2007.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standar
8、d without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the CEN Management Centre or to any CEN member.This European Standard exists in three official versions (English, French, German). A version in any other lang
9、uage made by translationunder the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as theofficial versions.CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,
10、France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR
11、 NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2007 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN ISO 4869-3:2007: EForeword This document (EN ISO 4869-3:2007) has been prepared by Technical Committee ISO/TC 43 “Aco
12、ustics“ in collaboration with Technical Committee CEN/TC 211 “Acoustics“, the secretariat of which is held by DS. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by January 2008, and conflicting nati
13、onal standards shall be withdrawn at the latest by January 2008. This document supersedes EN 24869-3:1993. This document has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Association, and supports essential requirements of EU Directive(s). For rela
14、tionship with EU Directive(s), see informative Annex ZA, which is an integral part of this document. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, C
15、zech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. Endorsement notice The text of ISO 4869-3:2007
16、 has been approved by CEN as EN ISO 4869-3:2007 without any modifications. EN ISO 4869-3:2007Reference numberISO 4869-3:2007(E)INTERNATIONAL STANDARD ISO4869-3First edition2007-07-01Acoustics Hearing protectors Part 3: Measurement of insertion loss of ear-muff type protectors using an acoustic test
17、fixture Acoustique Protecteurs individuels contre le bruit Partie 3: Mesurage de laffaiblissement acoustique des protecteurs du type serre-tte au moyen dun montage dessai acoustique EN ISO 4869-3:2007ii iiiForeword ISO (the International Organization for Standardization) is a worldwide federation of
18、 national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. Int
19、ernational organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with t
20、he rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval
21、by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 4869-3 was prepared by Technical Committee
22、ISO/TC 43, Acoustics, Subcommittee SC 1, Noise. This first edition of ISO 4869-3 cancels and replaces ISO/TR 4869-3:1989, which has been technically revised. The technical changes are as follows: a) the title has been changed and the standard has been revised; b) the content of the former subclause
23、on “test signal” has been included in the subclause “Measuring system”; c) the subclause “Measuring system” no longer contains specific requirements concerning the measuring system; d) Annex B, dealing with uncertainty, has been added. ISO 4869 consists of the following parts, under the general titl
24、e Acoustics Hearing protectors: Part 1: Subjective method for the measurement of sound attenuation Part 2: Estimation of effective A-weighted sound pressure levels when hearing protectors are worn Part 3: Measurement of insertion loss of ear-muff type protectors using an acoustic test fixture Part 4
25、: Measurement of effective sound pressure levels for level-dependent sound-restoration ear-muffs Technical Report Part 5: Method for estimation of noise reduction using fitting by inexperienced test subjects Technical Specification Part 6, Measurement of the active noise reduction of hearing protect
26、ors, is under preparation. EN ISO 4869-3:2007iv Introduction A Technical Report describing the use of an acoustic test fixture (ATF) to measure the insertion loss of ear-muff type protectors was published as ISO/TR 4869-3 in 1989. As testing laboratories around the world commonly use the ATF, it was
27、 decided that this Technical Report should be revised and changed into an International Standard. Compared to the original Technical Report, the most important aspect of this part of ISO 4869 is the specification of the ATF. The ATF specified herein is not intended to supplant those dummy heads whic
28、h include simulation of various anatomical features and which are used, for example, for development testing purposes. The method specified in this part of ISO 4869 does not provide results which are the same as those obtained by the subjective method, ISO 4869-1. EN ISO 4869-3:20071Acoustics Hearin
29、g protectors Part 3: Measurement of insertion loss of ear-muff type protectors using an acoustic test fixture 1 Scope This part of ISO 4869 specifies a method for measuring the insertion loss of ear-muff type hearing protectors using an acoustic test fixture. The method is applicable to the investig
30、ation of production spreads of performance as part of type approval or certification procedures, and to the investigation of the change of performance with age. It is intended to ensure that ear-muff hearing protector samples submitted for subjective testing of attenuation according to ISO 4869-1 ha
31、ve performances typical of the type. The method specified in this part of ISO 4869 is not applicable as the basic test for type approval. Performance data obtained by this method are not intended to be quoted as representing the real-ear sound attenuation of an ear-muff, nor the protection provided
32、by the ear-muff. For the testing of certain ear-muffs (such as those attached to safety helmets, or those with contoured ear-cups or ear-cushions, or supra-aural ear-muffs), the procedure described in this part of ISO 4869 might need to be modified. 2 Normative references The following referenced do
33、cuments 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 document (including any amendments) applies. ISO 48, Rubber, vulcanized or thermoplastic Determination of hardness (hardn
34、ess between 10 IRHD and 100 IRHD) ISO 4869-1, Acoustics Hearing protectors Part 1: Subjective method for the measurement of sound attenuation ISO/IEC Guide 98:1995, Guide to the expression of uncertainty in measurement (GUM) IEC 60263, Scales and sizes for plotting frequency characteristics and pola
35、r diagrams IEC 61260, Electroacoustics Octave-band and fractional-octave-band filters IEC 61094-4, Measurement microphones Part 4: Specifications for working standard microphones EN ISO 4869-3:20072 3 Terms and definitions For the purposes of this document, the following terms and definitions apply.
36、 3.1 hearing protector device worn by a person to reduce unwanted auditory effects from acoustic stimuli 3.2 ear-muff hearing protector consisting of a supra-aural ear-cup to be pressed against each pinna or of a circumaural ear-cup to be pressed against the head around the pinna NOTE The ear-cups c
37、an be pressed against the head with a special headband or neck-band or by means of a device attached to a safety helmet or other equipment. 3.3 head-strap flexible strap fitted to each cup, or to the headband close to the cup NOTE The strap can be adjusted to support the ear-muffs, usually for behin
38、d-the-head types, by resting on the top of the head. 3.4 acoustic test fixture ATF device that approximates certain dimensions of an average adult human head NOTE An ATF is used for measuring the insertion loss of hearing protectors of the ear-muff type and includes a microphone for measuring sound
39、pressure levels. 3.5 insertion loss algebraic difference, in decibels, between the one-third-octave-band sound pressure level measured by the microphone of the acoustic test fixture with the hearing protector absent and the sound pressure level with the hearing protector present 3.6 pink noise noise
40、 in which sound power spectral density is inversely proportional to frequency 3.7 acoustic isolation algebraic difference, in decibels, between the one-third-octave-band sound pressure level measured by the microphone of the acoustic test fixture with a specially designed sound isolation test cup ab
41、sent and the sound pressure level with the specially designed sound isolation test cup present 3.8 noise floor output level of the measurement system with the test signal switched off and a test cup providing sufficient acoustic isolation in position 3.9 reference point midpoint of a line connecting
42、 the centres of the two end faces of the acoustic test fixture EN ISO 4869-3:200734 Measurement principle The level of a test signal in a defined sound field is measured by a microphone located in an acoustic test fixture (ATF). The level is measured without and with the microphone being occluded by
43、 the ear-muff under test. The difference between the two measurement results is the insertion loss of the hearing protector. The ATF shall allow an ear-muff to be placed properly by positioning one ear-cup of the hearing protector over a measuring microphone. 5 Measurement of the insertion loss of e
44、ar-muffs 5.1 Acoustic test fixture (ATF) 5.1.1 General An example of an ATF is given in Figure 1. 5.1.2 Description The ATF shall be made of a non-magnetic material, for example aluminium alloy or brass. It shall be in the shape of a cylinder with its axis horizontal and with (145 1) mm between the
45、centres of the two end faces. The diameter of the cylinder shall be (135 5) mm. The angles of each of the two end faces shall be inclined towards the top at 4,5 0,5 to a vertical plane. The measuring microphone shall be of type WS1P or WS2P in accordance with IEC 61094-4. It shall be of the pressure
46、-operated condenser type. The microphone shall be placed with its centre axis coinciding with the centre axis of the cylinder. The centre of the microphone diaphragm shall be in the plane of one of the end faces of the cylinder on the centre line. See Figure 2. To reduce structure-borne sound, the A
47、TF shall be supported in the test sound field with a resilient mounting so as to achieve a sufficiently low noise floor. The vertical and horizontal diameters shall be marked at the end faces of the ATF, along with two or three concentric circles of suitable radius to help in positioning the ear-muf
48、f properly. The marking shall not produce any acoustical leakage. It may be necessary to equalize the static pressure under the ear-muff during fitting. This may be achieved by: a) a capillary tube that is placed between the cushion and the ATF surface during the fitting of the ear-muff to the fixtu
49、re, and which is removed before the measurements; care shall be taken not to permanently deform the cushion; b) a fixed capillary tube connecting the cavity under the ear-muff to the external air; the tube shall be of diameter 0,5 mm, of length 25 mm, parallel with and near to the axis of the microphone of the acoustic test fixture, partly closed by a wire of diameter 0,4 mm and combined with a tube of diameter about 3 mm extending from the bottom of the cylinder perpendicular to the microphone axis. 5.1.3 Spacer A spac
