1、| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BRITISH STANDARD BS 7580 : Part 1 : 1997 I
2、mplementing Amendment No. 1, not published separately ICS 17.140.50 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Specification for The verification of sound level meters Part 1. Comprehensive procedureBS 7580 : Part 1 : 1997 Issue 3, April 1999 This British Standard, having
3、 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 15 June 1992 BSI 04-1999 The following BSI references relate to the work on this standard: Committee reference EEL/24 Draft for
4、 comment 90/32217 DC ISBN 0 580 20908 3 Amendments issued since publication Amd. No. Date Text affected 9278 January 1997 Renumbered BS 7580 : 1992 as BS 7580-1 : 1997, and implemented various textual changes (see Foreword) 10446 April 1999 Indicated by a sideline on pages i, ii, 1, 2 and the inside
5、 back cover 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/24, upon which the following bodies were represented: British Hearing Aid Industry Association
6、 British Medical Association British Society of Audiology British Telecommunications plc Confederation of British Industry Department of Health Department of Trade and Industry (National Physical Laboratory) Health and Safety Executive Institute of Acoustics Institute of Sound and Vibration Research
7、 Institution of Electrical Engineers Medical Research Council Ministry of Defence National Health Services Royal Aeronautical Society Royal National Institute for the Deaf Society of Environmental Engineers Society of Hearing Aid Audiologists Limited University of ExeterIssue 2, April 1999 BS 7580 :
8、 Part 1 : 1997 BSI 04-1999 a Summary of pages The following table identifies the current issue of each page. Issue 1 indicates that a page has been introduced for the first time by amendment. Subsequent issue numbers indicate an updated page. Vertical sidelining on replacement pages indicates the mo
9、st recent changes (amendment, addition, deletion). Page Issue Page Issue Front cover Inside front cover a b i ii 1 3 3 2 blank 2 2 3 2 3 4 5 6 Inside back cover Back cover 3 3 2 2 blank 3 3b blankIssue 2, April 1999 BS 7580 : Part 1 : 1997 BSI 04-1999 i | | Contents Page Committees responsible Insid
10、e front cover Foreword ii Specification 1 0 Introduction 1 1 Scope 1 2 References 1 3 Definitions 1 4 Frequency of verification 1 5 Verification procedure 1 6 Information to be provided on the calibration certificate 5 List of references Inside back coverBS 7580 : Part 1 : 1997 Issue 2, April 1999 i
11、i BSI 04-1999 | | | | | | Foreword This British Standard has been prepared by Technical Committee EPL/29 (formerly EEL/24). Amendment No. 1 : 1997 to BS 7580 : 1992 renumbered it as BS 7580 : Part 1 : 1997. Amendment No. 1 : 1997 also updated the references and broadened the requirements for the bod
12、y carrying out the procedure. BS 7580 : 1992 was renumbered to take account of the publication of BS 7580 : Part 2 : 1997 which specifies an abbreviated verification procedure for Type 2 sound level meters. The procedure for the verification of sound level meters specified herein is based upon the s
13、pecifications for sound level meters given in BS EN 60651 : 1994 (which replaced BS 5969 : 1981) and BS EN 60804 : 1994 (formerly BS 6698 : 1986). The draft international standard IEC 61672 Sound level meters, when published as a BS EN standard, will replace BS EN 60651 : 1994 and BS EN 60804 : 1994
14、. IEC 61672 specifies wider tolerances to include measurement uncertainties which were not included in BS EN 60651 and BS EN 60804. In preparing this British Standard, Technical Committee EPL/29 found it necessary to interpret certain parts of BS EN 60651 and BS EN 60804 which were considered ambigu
15、ous, although the test principles used in these standards have been preserved as far as possible. The set of tests is based closely on the recommendations in OIML Recommendation 58 Sound level meters 1 and Recommendation 88 Integrating-averaging sound level meters 2, published by the International O
16、rganization for Legal Metrology (OIML). BS 3539 : 1986 deals with the verification of sound level meters, but only for specific application to the measurement of motor vehicle noise. This British Standard specifies a generally applicable procedure for verification of instruments for a wide range of
17、applications, but incorporates sufficient tests that an instrument conforming to 2.1 to 2.4 of BS 3539 : 1986 and conforming to this standard is deemed to conform fully to BS 3539 : 1986. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Stan
18、dards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. BSI 04-1999 1 Issue 3, April 1999 BS 7580 : Part 1 : 1997 1) Repeated from PD 6461 : Part 2 : 1980. Specification 0 Introduction Detailed performance req
19、uirements for sound level meters and integrating-averaging sound level meters are specified in BS EN 60651 : 1994 and BS EN 60804 : 1994, respectively. Instruments conforming to these standards are used extensively for measuring noise, often to satisfy regulatory requirements. To ensure that these m
20、easurements are well-founded, it is important that the measuring instrument is operating in conformance to the standard to which it was manufactured. However, although BS EN 60651 : 1994 and BS EN 60804 : 1994 provide full specifications relevant to pattern evaluation, they do not deal explicitly wi
21、th the periodic verification of conformance. The purpose of this standard is to specify a limited but sufficient range of tests, based on BS EN 60651 : 1994 and BS EN 60804 : 1994, to verify the accuracy of the instrument at regular intervals. 1 Scope This British Standard specifies a procedure for
22、the periodic verification of conformance of a sound level meter or integrating-averaging sound level meter to BS EN 60651 : 1994 or BS EN 60804 : 1994, respectively, including a series of tests and the information to be shown on the calibration certificate. This standard is applicable to sound level
23、 meters originally manufactured in accordance with BS EN 60651 : 1994 and BS EN 60804 : 1994. The tests in this standard are therefore based on those in BS EN 60651 : 1994 and BS EN 60804 : 1994 and are intended simply to verify the correct operation of the instrument. This standard is also applicab
24、le to sound level meters for the measurement of motor vehicle noise, in so far as an instrument which conforms both to this standard and to 2.1 to 2.4 of BS 3539 : 1986 is deemed also to conform fully to BS 3539 : 1986. 2 References 2.1 Normative references This British Standard incorporates, by ref
25、erence, provisions from specific editions of other publications. These normative references are cited at the appropriate points in the text and the publications are listed on the inside back cover. Subsequent amendments to, or revisions of, any of these publications apply to this British Standard on
26、ly when incorporated in it by updating or revision. | 2.2 Informative references This British Standard refers to other publications that provide information or guidance. Editions of these publications current at the time of issue of this standard are listed on the inside back cover, but reference sh
27、ould be made to the latest editions. 3 Definitions For the purposes of this British Standard the definitions given in BS EN 60651 : 1994 and BS EN 60804 : 1994 apply together with the following. 3.1 pattern evaluation 1) The examination of one or more measuring instruments of the same pattern which
28、are submitted by a manufacturer to a national service of legal metrology; this examination includes the tests necessary for the approval of the pattern. 3.2 verification The demonstration, by application of a limited series of tests, that a measuring instrument conforms to a set of key requirements
29、based on the specifications for sound level meters in BS EN 60651 : 1994 and BS EN 60804 : 1994. 3.3 initial verification 1) The verification of a new measuring instrument which has not been verified previously. 3.4 periodic verification The subsequent verification of a measuring instrument carried
30、out at regular intervals. 4 Frequency of verification 4.1 General Verification shall be performed at least every two years. 4.2 Verification after repair Verification shall be performed on an instrument before further use if it has undergone a repair which is likely to have affected its performance.
31、 NOTE. Repairs necessitated by the failure of electronic components or transducers are likely to affect the performance of the instrument, whereas replacement of switches or battery leads is unlikely to have an effect. 5 Verification procedure 5.1 General The calibrations of the equipment used for t
32、he verification of the sound level meter and the calibration of the sound calibrator shall be traceable to national standards. NOTE 1. In the UK acoustic calibration laboratories are National Accreditation of Measurement and Sampling (NAMAS) accredited through the United Kingdom Accreditation Servic
33、e (UKAS); the relevant national metrology institute is the National Physical Laboratory (NPL).2 BSI 04-1999 BS 7580 : Part 1 : 1997 Issue 3, April 1999 | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | No test specified in 5.3 to 5.6 shall be omitted from the ve
34、rification procedure unless the instrument does not possess the facility tested. The tolerances given in this standard and in BS EN 60651 : 1994, BS EN 60804 : 1994 and BS EN 60942 : 1998 (which superseded BS 7189 : 1989) do not take into account any measurement uncertainty of the laboratory perform
35、ing the verification. The measured values obtained during a verification shall not be extended by any measurement uncertainty when assessing whether an instrument conforms to this standard. Conformity is demonstrated when all measured values are within the specified tolerances. NOTE 2. It is recomme
36、nded that the calibration certificate states, if appropriate, that verification does not accommodate measurement uncertainty. 5.2 Submission for verification The sound level meter shall be submitted for verification together with its instruction manual, if required by the calibration laboratory, and
37、 a sound calibrator. The sound calibrator shall conform to BS EN 60942 : 1998 or to BS 7189 : 1989, depending on the standard to which it was originally manufactured. The instruction manual shall contain the information required by 11.2 of BS EN 60651 : 1994 or of BS EN 60804 : 1994, as appropriate.
38、 Information shall also be provided on the corrections needed to perform the tests in 5.5.4 and 5.6. The sound calibrator shall itself have been calibrated within the previous year, using equipment whose calibrations are traceable to national standards, and shall be supplied with a calibration certi
39、ficate. The certificate shall state the sound pressure level, and frequency and either the total distortion (for sound calibrators originally manufactured in accordance with BS EN 60942 : 1998), or the total harmonic distortion (for calibrators originally manufactured in accordance with BS 7189 : 19
40、89), generated by the sound calibrator when it is coupled to an appropriate model of microphone. The model of microphone shall be such that manufacturers corrections are available to convert this level for free-field use with the model of microphone fitted to the sound level meter. These data shall
41、be consistent with conformity to BS EN 60942 : 1998 or BS 7189 : 1989, as appropriate, for the sound calibrator class specified by the manufacturer. 5.3 Preliminary inspection Prior to any measurements, the instrument, microphone and sound calibrator shall be visually inspected, and all controls ope
42、rated to ensure that they are in working order. It shall be established that the instrument power supply is within the operating limits specified by the manufacturer. 5.4 Setting up The sensitivity of the sound level meter shall be checked using the sound calibrator specified in 5.2 and if necessary
43、 adjusted according to the sound level meter manufacturers instructions and the data in the calibration certificate for the sound calibrator. 5.5 Electrical tests 5.5.1 General The electrical tests specified in 5.5.2 to 5.5.12 shall be performed using an electrical signal substituted for the microph
44、one. NOTE 1. 4.7 of BS EN 60651 : 1994 and 4.8 of BS EN 60804 : 1994 require the manufacturer to provide the means to substitute an electrical signal for the microphone for the purpose of performing tests on the complete instrument without the microphone. The actual method of substitution will vary
45、depending on the construction and component parts of the instrument. The three most important situations are as follows. a) Where the sound level meter is fitted with a detachable condenser or piezoelectric microphone, the microphone should be replaced by an equivalent capacitance within a tolerance
46、 of 20 %, unless a closer tolerance is specified by the manufacturer, in series with a low-impedance electrical signal source. b) Where the preamplifier is an integral part of the microphone, the method of substitution specified by the manufacturer should be used, and corrections used to take accoun
47、t of the preamplifier performance. c) Where access to the point of application of the electrical signal is restricted, for example when it is inside the case of the instrument, the manufacturers instructions should be followed on how to gain access to this point. NOTE 2. Except where stated otherwis
48、e these tests should, if possible, be carried out with the instrument set to frequency weighting A. 5.5.2 Self-generated noise With the instrument set to the lowest measuring range, and with the electrical signal specified in 5.5.1 set to zero, the reading obtained shall be recorded for each of the
49、frequency weightings provided. NOTE 1. In carrying out this test care should be taken to ensure that the indication is not affected by external electrical or electromagnetic fields. NOTE 2. It is recognized that with the passage of time the level of self-generated noise can exceed the maximum specified in 6.6 of BS EN 60651 : 1994, without adversely affecting the accuracy of measurements of higher sound pressure levels. 5.5.3 Linearity The linearity of the sound level meter shall be tested relative to the reference sound pressure level, as indicated on the reference range,
