ISO 2151-2004

Reference number ISO 2151:2004(E) © ISO 2004 INTERNATIONAL STANDARD ISO 2151 Second edition 2004-02-01 Acoustics — Noise test code for compressors and vacuum pumps — Engineering method (Grade 2) Acoustique — Code d'essai acoustique pour les compresseurs et les pompes à vide — Méthode d'expertise (classe de précision 2) Copyright International Organization for Standardization Reproduced by IHS under license with ISO Not for ResaleNo reproduction or networking permitted without license from IHS - - ` ` , ` ` , - ` - ` , , ` , , ` , ` , , ` - - - ISO 2151:2004(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. 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ISO copyright office Case postale 56 • CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyright@iso.org Web www.iso.org Published in Switzerland ii © ISO 2004 – All rights reserved Copyright International Organization for Standardization Reproduced by IHS under license with ISO Not for ResaleNo reproduction or networking permitted without license from IHS - - ` ` , ` ` , - ` - ` , , ` , , ` , ` , , ` - - - ISO 2151:2004(E) © ISO 2004 – All rights reserved iii Contents Page Foreword............................................................................................................................................................ iv Introduction ........................................................................................................................................................ v 1 Scope...................................................................................................................................................... 1 2 Normative references ........................................................................................................................... 2 3 Terms and definitions........................................................................................................................... 2 4 Sound power level determination ....................................................................................................... 5 4.1 General ................................................................................................................................................... 5 4.2 Uncertainty............................................................................................................................................. 6 4.3 Test arrangement .................................................................................................................................. 6 5 Emission sound pressure level determination at the work station ................................................. 7 5.1 Work station .......................................................................................................................................... 7 5.2 Determination of LpWSA from LWA...................................................................................................... 8 5.3 Method for determination of LpWSA when LWA is not to be determined ........................................ 9 6 Mounting, loading and operating conditions of compressor or vacuum pump during noise tests.............................................................................................................................................. 9 6.1 General ................................................................................................................................................... 9 6.2 Mounting ................................................................................................................................................ 9 6.3 Loading and operating conditions ...................................................................................................... 9 7 Test report............................................................................................................................................ 10 8 Declaration and verification of noise emission values ................................................................... 10 Annex A (informative) Example test reports.................................................................................................. 11 Annex B (informative) Model form for declared noise emission values..................................................... 17 Annex C (normative) Parallelepiped measurement surface ........................................................................ 18 Annex D (normative) Hemispherical measurement surface ........................................................................ 20 Annex E (informative) Examples of reference box for different machines................................................. 22 Bibliography ..................................................................................................................................................... 25 Copyright International Organization for Standardization Reproduced by IHS under license with ISO Not for ResaleNo reproduction or networking permitted without license from IHS - - ` ` , ` ` , - ` - ` , , ` , , ` , ` , , ` - - - ISO 2151:2004(E) iv © ISO 2004 – All rights reserved Foreword ISO (the International Organization for Standardization) is a worldwide federation of 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. International 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 the 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 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 2151 was prepared by Technical Committee ISO/TC 118, Compressors, pneumatic tools and pneumatic machines, Subcommittee SC 6, Air compressors. This second edition cancels and replaces the first edition (ISO 2151:1972), which has been technically revised. Copyright International Organization for Standardization Reproduced by IHS under license with ISO Not for ResaleNo reproduction or networking permitted without license from IHS - - ` ` , ` ` , - ` - ` , , ` , , ` , ` , , ` - - - ISO 2151:2004(E) © ISO 2004 – All rights reserved v Introduction The noise test code presented by this International Standard describes methods for determining and presenting the acoustical characteristics of compressors and vacuum pumps, i.e. the total noise level from the compressor or vacuum pump expressed as sound power level, or the emission sound pressure level at the work station or other specified positions. Based on current industry practice, this noise test code requires the compressor or vacuum pump under test to be run under conditions representing the noisiest operation in typical usage — full-load for compressors and off-load for vacuum pumps. It needs to be noted that operators' exposure to noise depends upon the characteristics of individual applications and environmental factors beyond the control of the manufacturers of compressors and vacuum pumps. This International Standard does not give requirements for octave band analysis, however, where there is an interest this can be undertaken. Copyright International Organization for Standardization Reproduced by IHS under license with ISO Not for ResaleNo reproduction or networking permitted without license from IHS - - ` ` , ` ` , - ` - ` , , ` , , ` , ` , , ` - - - Copyright International Organization for Standardization Reproduced by IHS under license with ISO Not for ResaleNo reproduction or networking permitted without license from IHS - - ` ` , ` ` , - ` - ` , , ` , , ` , ` , , ` - - - INTERNATIONAL STANDARD ISO 2151:2004(E) © ISO 2004 – All rights reserved 1 Acoustics — Noise test code for compressors and vacuum pumps — Engineering method (Grade 2) 1 Scope This International Standard specifies methods for the measurement, determination and declaration of the noise emission from portable and stationary compressors and vacuum pumps. It prescribes the mounting, loading and working conditions under which measurements are to be made, and includes measurement or determination of the noise emission expressed as  the sound power level under specified load conditions,  the emission sound pressure level at the work station under specified load conditions. It is applicable to  compressors for various types of gases,  oil-lubricated air compressors,  oil-flooded air compressors,  water injected air compressors,  oil-free air compressors,  compressors for handling hazardous gases (gas compressors),  compressors for handling oxygen,  compressors for handling acetylene,  high-pressure compressors [over 4 Mpa (40 bar)],  compressors for application at low inlet temperatures, i.e. below 0 °C,  large compressors (over 1 000 kW input power),  portable and skid-mounted air compressors, and  rotary positive displacement blowers and centrifugal blowers and exhausters in applications u 0,2 MPa (u 2 bar). It is not applicable to  compressors for gases other than acetylene having a maximum allowable working pressure of less than 0,5 bar/0,05 MPa,  refrigerant compressors used in refrigerating systems or heat pumps,  hand-held portable compressors. Copyright International Organization for Standardization Reproduced by IHS under license with ISO Not for ResaleNo reproduction or networking permitted without license from IHS - - ` ` , ` ` , - ` - ` , , ` , , ` , ` , , ` - - - ISO 2151:2004(E) 2 © ISO 2004 – All rights reserved 2 Normative references The following referenced documents 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 3744:1994, Acoustics — Determination of sound power levels of noise sources using sound pressure — Engineering method in an essentially free field over a reflecting plane ISO 4871:1996, Acoustics — Declaration and verification of noise emission values of machinery and equipment ISO 9614-1:1993, Acoustics — Determination of sound power levels of noise sources using sound intensity — Part 1: Measurement at discrete points ISO 9614-2:1996, Acoustics — Determination of sound power levels of noise sources using sound intensity — Part 2: Measurement by scanning ISO 11201:1995, Acoustics — Noise emitted by machinery and equipment — Measurement of emission sound pressure levels at a work station and at other specified positions — Engineering method in an essentially free field over a reflecting plane ISO 11202:1995, Acoustics — Noise emitted by machinery and equipment — Measurement of emission sound pressure levels at a work station and at other specified positions — Survey method in situ ISO 11203:1995, Acoustics — Noise emitted by machinery and equipment — Determination of emission sound pressure levels at a work station and at other specified positions from the sound power level IEC 61672-1:2002, Electroacoustics — Sound level meters — Specifications 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 compressor machine which compresses air, gases or vapours to a pressure higher than the inlet pressure NOTE A compressor comprises the bare compressor itself, the prime mover and any component or device supplied with the compressor. 3.2 vacuum pump device for creating, improving and/or maintaining vacuum NOTE A vacuum pump comprises the bare pump, the prime mover and any component or device supplied with the vacuum pump. 3.3 emission airborne sound radiated by a well-defined noise source (e.g. the machine under test) under specified operating and mounting conditions NOTE 1 Adapted from ISO 11203:1995. NOTE 2 Noise emission values can be incorporated in a product label and/or published in a product specification. The basic noise emission descriptors are the sound power level of the product itself and the emission sound pressure levels at the work station and at other specified positions in the vicinity of the product (if any). Copyright International Organization for Standardization Reproduced by IHS under license with ISO Not for ResaleNo reproduction or networking permitted without license from IHS --``,``,-`-`,,`,,`,`,,`--- ISO 2151:2004(E) © ISO 2004 – All rights reserved 3 3.4 emission sound pressure p sound pressure, expressed in pascals, at a specified position near a noise source, when the source is in operation under specified operating and mounting conditions on a reflecting plane surface, corrected for background noise and reflections from room surfaces other than the plane over which the machine under test is placed NOTE Adapted from ISO 11203:1995. 3.5 emission sound pressure level Lp ten times the logarithm to the base 10 of the ratio of the square of the emission sound pressure to the square of the reference sound pressure, expressed in decibels, and measured with a particular time weighting and a particular frequency weighting selected from those defined in IEC 61672-1:2002 EXAMPLE A-weighted emission sound pressure level, LpA. NOTE 1 The reference sound pressure is 20 µPa. NOTE 2 LpA levels are established as LpAeqT time-averaged sound pressure levels measured with an integrating- averaging sound level meter meeting the requirements of IEC 61672-1:2002. LpAeqT is usually abbreviated to LpA. For further details of LpAeqT see ISO 3744:1994, 3.2.1. NOTE 3 Adapted from ISO 11203:1995. 3.6 sound power W rate per unit time, expressed in watts, at which airborne sound energy is radiated by a source [ISO 3744:1994] 3.7 sound power level LW ten times the logarithm to the base 10 of the ratio of the sound power radiated by the source under test to the reference sound power, expressed in decibels NOTE 1 The frequency weighting or the width of the frequency band must be indicated. For example, A-weighted sound power level LWA. NOTE 2 The reference sound power is 1 pW (1 pW = 10−12 W). NOTE 3 Adapted from ISO 3744:1994. 3.8 sound intensity product of the sound pressure at a point and the associated particle velocity NOTE 1 It is a vectorial quantity. NOTE 2 See ISO 9614-1 and ISO 9614-2 for further guidance on sound intensity. Copyright International Organization for Standardization Reproduced by IHS under license with ISO Not for ResaleNo reproduction or networking permitted without license from IHS - - ` ` , ` ` , - ` - ` , , ` , , ` , ` , , ` - - - ISO 2151:2004(E) 4 © ISO 2004 – All rights reserved 3.9 partial sound power Pi time-averaged rate of flow of sound energy through an element (segment) of a measurement surface, given by ni i i i iP I S I S= × = × GG where Ini is the signed magnitude of the normal sound intensity component measured at position i on the measurement surface; Si is the area of the segment of surface associated with point i. 3.10 background noise correction K1 correction term to account for the influence of background noise on the surface sound pressure level, expressed in decibels NOTE 1 K1 is frequency dependent. NOTE 2 The correction in the case of A-weighting is denoted K1A. NOTE 3 Adapted from ISO 3744:1994. 3.11 environmental correction K2 correction term to account for the influence of reflected or absorbed sound on the surface sound pressure level, expressed in decibels NOTE 1 K2 is frequency dependent. NOTE 2 The correction in the case of A-weighting is denoted K2A. NOTE 3 Adapted from ISO 3744:1994. 3.12 reference box hypothetical surface which is the smallest rectangular parallelepiped that just encloses the source and terminates on the reflecting plane [ISO 3744:1994] 3.13 measurement surface hypothetical surface of area S, enveloping the source, on which the measurements are made NOTE The measurement surface terminates on the reflecting plane. 3.14 measurement distance distance, d, from the reference box to the parallelepiped measurement surface, or radius, r, of the hemispherical measurement surface NOTE Adapted from ISO 3744:1994. Copyright International Organization for Standardization Reproduced by IHS under license with ISO Not for ResaleNo reproduction or networking permitted without license from IHS - - ` ` , ` ` , - ` - ` , , ` , , ` , ` , , ` - - - ISO 2151:2004(E) © ISO 2004 – All rights reserved 5 3.15 noise emission declaration information on the noise emitted by the machine given by the manufacturer or supplier in technical documents or other literature concerning noise emission values 3.16 uncertainty K value of the total uncertainty associated with a measured noise emission value and the production, expressed in decibels [ISO 4871:1996] NOTE See also 4.2. 3.17 declared dual-number noise emission value L, K noise emission value, L, and its associated uncertainty, K, given in the noise emission declaration NOTE 1 The symbols used are  A-weighted sound power level, LWAd, with uncertainty, KWAd, and  A-weighted emission sound pressure level, LpAd, with uncertainty, KpAd. NOTE 2 Adapted from ISO 4871:1996. 3.18 work station position in the vicinity of the compressor or vacuum pump under test, intended for the operator NOTE 1 For the purposes of this International Standard, this is the surface enveloping the machine on test at a distance of 1 m from the reference box (see 3.12). NOTE 2 Adapted from ISO 11203:1995. 3.19 A-weighted emission sound pressure level at the work station LpWSA energy average of the A-weighted emission sound pressure levels at the work station 4 Sound power level determination 4.1 General The sound power level s