1、 Reference number ISO/TS 7849-1:2009(E) ISO 2009TECHNICAL SPECIFICATION ISO/TS 7849-1 First edition 2009-03-15 Acoustics Determination of airborne sound power levels emitted by machinery using vibration measurement Part 1: Survey method using a fixed radiation factor Acoustique Dtermination des nive
2、aux de puissance acoustique ariens mis par les machines par mesurage des vibrations Partie 1: Mthode de contrle employant un facteur de rayonnement fixe ISO/TS 7849-1:2009(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobes licensing policy, this file may be pri
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7、1 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO 2009 All rights reservedISO/TS 7849-1:2009(E) ISO 2009 All rights reserved iii Contents Page Foreword iv Introduction v 1 Scope . 1 2 Normative references . 1 3 Terms and definitions. 2 4 Principle. 4
8、5 Measuring instrumentation 5 5.1 General. 5 5.2 Vibration transducer. 5 5.3 Non-contacting transducers 5 5.4 Amplifier 6 5.5 Integrator . 6 5.6 Calibration . 6 6 Installation and operation of source under test 6 6.1 General. 6 6.2 Description of the machine 7 6.3 Installation . 7 6.4 Operating cond
9、itions 7 7 Determination of the vibratory velocity on the vibrating measurement surface . 7 7.1 General. 7 7.2 Vibrating measurement surface 7 7.3 Number of measurement positions 8 7.4 Environmental conditions 8 7.5 Measurement procedure 9 7.6 Mounting of the vibration transducer. 9 8 Calculations.
10、9 8.1 Correction for extraneous vibratory velocity. 9 8.2 Determination of the mean A-weighted vibratory velocity level on the vibrating measurement surface. 10 8.3 Calculation of the upper limit of the A-weighted airborne sound power level caused by radiation of structure vibration generated sound
11、. 11 9 Measurement uncertainty 11 10 Information to be recorded 13 10.1 Machine under test . 13 10.2 Measurement conditions . 13 10.3 Measuring instrumentation 13 10.4 Acoustical data . 13 Annex A (informative) Use of the vibration transducer 14 Annex B (informative) Guidance on the development of i
12、nformation on measurement uncertainty 16 Bibliography . 19 ISO/TS 7849-1:2009(E) iv ISO 2009 All rights reservedForeword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards
13、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 pa
14、rt 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
15、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. In other circumstances, particularly whe
16、n there is an urgent market requirement for such documents, a technical committee may decide to publish other types of document: an ISO Publicly Available Specification (ISO/PAS) represents an agreement between technical experts in an ISO working group and is accepted for publication if it is approv
17、ed by more than 50 % of the members of the parent committee casting a vote; an ISO Technical Specification (ISO/TS) represents an agreement between the members of a technical committee and is accepted for publication if it is approved by 2/3 of the members of the committee casting a vote. An ISO/PAS
18、 or ISO/TS is reviewed after three years in order to decide whether it will be confirmed for a further three years, revised to become an International Standard, or withdrawn. If the ISO/PAS or ISO/TS is confirmed, it is reviewed again after a further three years, at which time it must either be tran
19、sformed into an International Standard or be withdrawn. 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/TS 7849-1 was prepared by Technical Commi
20、ttee ISO/TC 43, Acoustics, Subcommittee SC 1, Noise. This first edition of ISO/TS 7849-1, together with ISO/TS 7849-2, cancel and replace the first edition of ISO/TR 7849:1987, which has been technically revised. ISO/TS 7849 consists of the following parts, under the general title Acoustics Determin
21、ation of airborne sound power levels emitted by machinery using vibration measurement: Part 1: Survey method using a fixed radiation factor Part 2: Engineering method including determination of the adequate radiation factor The following part is under preparation: Part 3: Amplitude and phase measure
22、ments ISO/TS 7849-1:2009(E) ISO 2009 All rights reserved v Introduction This part of ISO/TS 7849 gives a procedure for the determination of the sound power of the airborne noise caused by machinery vibration. The determination of airborne noise emission of a machine by measuring vibration of the mac
23、hines outer surface may be of interest when: undesired background noise (e.g. noise from other machines or sound reflected by room boundaries) is high compared with the noise radiated directly by the machine under test; noise radiated by structure vibration is to be separated from noise of aerodynam
24、ic origin; noise radiated by structure vibration is high compared to the aerodynamic component so that the total noise radiation is predominantly affected by the structure vibration; sound intensity measurement techniques ISO 9614 (all parts) 12 cannot easily be applied; structure vibration generate
25、d noise from only a part of a machine, or from a component of a machine set, is to be determined in the presence of noise from the other parts of the whole machine. ISO/TS 7849 (all parts) describes methods for the determination of the airborne noise emission of a machine caused by vibration of its
26、outer surface, expressed by the associated A-weighted airborne sound power being related to normalized meteorological conditions. This airborne sound power is determined under the assumption that this quantity is proportional to the mean square value of the normal component of the velocity averaged
27、over the area of the vibrating outer surface of the machine, and is directly proportional to the area of the vibrating surface. The calculation of the airborne sound power needs data of the radiation factor in principle. For this part of ISO/TS 7849 a radiation factor of 1 is assumed allowing the de
28、termination of an upper limit for the radiated A-weighted sound power level. For typical machines this upper limit may exceed the true A-weighted sound power level determined by the intensity procedure of ISO 9614 (all parts) 12by up to 10 dB. The A-weighted sound power level determined according to
29、 this part of ISO/TS 7849 can be used for sound power level comparison of relevant vibrating machinery noise of the same family with similar design. TECHNICAL SPECIFICATION ISO/TS 7849-1:2009(E) ISO 2009 All rights reserved 1 Acoustics Determination of airborne sound power levels emitted by machiner
30、y using vibration measurement Part 1: Survey method using a fixed radiation factor 1 Scope This part of ISO/TS 7849 gives basic requirements for reproducible methods for the determination of an upper limit for the A-weighted sound power level of the noise emitted by machinery or equipment by using s
31、urface vibration measurements. The method is only applicable to noise which is emitted by vibrating surfaces of solid structures and not to noise generated aerodynamically. This vibration measurement method is especially applicable in cases where accurate direct airborne noise measurements, e.g. as
32、specified in ISO 3746 7 , ISO 3747 8 , and ISO 9614 (all parts) 12 , are not possible because of high background noise or other parasitic environmental interferences; or if a distinction is required between the total radiated sound power and its structure vibration generated component. NOTE 1 One of
33、 the applications of this part of ISO/TS 7849 is the distinction between the radiation of airborne sound power generated by structure vibration and the aerodynamic sound power components. Such a distinction is not feasible with ISO 3746 7and ISO 9614 (all parts) 12 . NOTE 2 Problems can occur if the
34、 noise is generated by small parts of machinery surfaces (sliding contacts, e.g. slip ring brush or the commutator and the brush in electrical machines). The methods described in this part of ISO/TS 7849 apply mainly to processes that are stationary with respect to time. 2 Normative references The f
35、ollowing 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 5348, Mechanical vibration and shock Mechanical mo
36、unting of accelerometers ISO/IEC Guide 98-3, Uncertainty of measurement Part 3: Guide to the expression of uncertainty in measurement (GUM:1995) IEC 61672-1, Electroacoustics Sound level meters Part 1: Specifications ISO/TS 7849-1:2009(E) 2 ISO 2009 All rights reserved3 Terms and definitions For the
37、 purposes of this document, the following terms and definitions apply. 3.1 structure vibration generated sound airborne sound caused by structure vibration in the audible frequency range NOTE For the purposes of this part of ISO/TS 7849, structure vibration generated sound is determined either from
38、the vibratory velocity or the vibratory acceleration of the surface of the solid structure. 3.2 machine airborne sound power level measurement equipment which incorporates a single or several noise sources 3.3 vibratory velocity v root-mean square (r.m.s.) value of the component of the velocity of a
39、 vibrating surface in the direction normal to the surface NOTE 1 The vibratory velocity, v, is the time integral of the vibratory acceleration, whose r.m.s. value is given for sinusoidal vibration by: 2 a v f = (1) where a is the r.m.s. acceleration; f is the frequency. The vibratory velocity, v, is
40、 the time derivative of the vibratory displacement, s, ds/dt. For sinusoidal vibration, the r.m.s. velocity, v, is given by: 2 vf s = (2) where s is the r.m.s. displacement. NOTE 2 In this part of ISO/TS 7849, the vibratory velocity is usually applied with A-weighting, denoted v A . 3.4 A-weighted v
41、ibratory velocity level L vAten times the logarithm to the base 10 of the ratio of the square of the r.m.s. value of the A-weighted vibratory velocity, v A , to the square of a reference value, v 0 , expressed in decibels: 2 A A 2 0 10 lg dB v v L v = (3) ISO/TS 7849-1:2009(E) ISO 2009 All rights re
42、served 3 where v Ais the A-weighted r.m.s. value of the vibratory velocity, in metres per second 1) ; v 0is the reference value for the velocity and is equal to 5 10 8m/s 2) . NOTE For airborne and structure vibration generated sound, the reference value, v 0= 50 nm/s has the property that it leads,
43、 together with p 0= 2 10 5Pa, to the reference value of the intensity level I 0= 1 10 12W/m 2and to the characteristic impedance of air by p 0 /v 0= 400 N s/m 3 . 3.5 A-weighted radiation factor Afactor expressing the efficiency of sound radiation given by: A A 2 cA P Z Sv = (4) where P Ais the A-we
44、ighted airborne sound power emitted by the vibrating surface of the machine, determined according to ISO 9614 (all parts) 12 ; S is the area of the defined outer surface of the machine under test (vibrating measurement surface; see 3.8); 2 A v is the squared A-weighted r.m.s. value of the vibratory
45、velocity averaged over S; Z cis the characteristic impedance of air. NOTE The four quantities A , P A , 2 A , v and Z crelate to the same period of time and to the same meteorological conditions (atmospheric temperature, , and barometric pressure, B). 3.6 A-weighted airborne sound power level L WAte
46、n times the logarithm to the base 10 of the ratio of the A-weighted airborne sound power emitted by the surface of a machine, P A , to a reference value, P 0 , expressed in decibels A A 0 10 lg dBW P L P = (5) where the reference value, P 0 , is 10 12W 3.7 upper limit of A-weighted airborne sound po
47、wer level L WA,maxA-weighted airborne sound power level determined in accordance with the method described in this part of ISO/TS 7849 1) A subscript “eff” is dropped, since only r.m.s. values are used throughout this part of ISO/TS 7849. 2) In ISO 1683 1 , two reference values for the velocity leve
48、l are mentioned: v 0= 10 9m/s and 5 10 8m/s. The latter is intended for cases of airborne and structure vibration generated sound and is therefore used in this part of ISO/TS 7849. A choice of v 0= 10 9m/s results in a vibratory velocity level which is 34 dB higher than the level used in this part o
49、f ISO/TS 7849. Therefore, if v 0= 10 9m/s is used, subtract 34 dB from the right-hand sides of Equations (7), (8), and (11). ISO/TS 7849-1:2009(E) 4 ISO 2009 All rights reserved3.8 vibrating measurement surface surface of a machine radiating the structure vibration generated sound where the measurement positions are located NOTE Its area is designated by the symbol S. 3.9 extraneous vibratory velocity level vibratory velocity level, caused by all sources othe
