1、UDC 534.61 : 62 : 534.835.46 DEUTSCHE NORM April 1984 Measurement of noise emitted by machines Airborne noise emission Enveloping surface method Basic method, divided into 3 grades of accuracy DIN 45 635 Part 1 Geruschmessung an Maschinen: Luftschallemission; Hllflchen-Verfahren; Rahmenverfahren fr
2、3 Genauigkeitsklassen Supersedes January 1972 edition In keeping with current practice in standards published by the International Organization forStandardization (ISO), a comma has been used throughout as the decimal marker. See Explanatory notes for connection with International Standards IS0 3740
3、 - 1980, IS0 3744 -1981, IS0 3745 - 1977, IS0 3746-1979, ISOIDIS 3748- 1983 and ISOIDIS 6081.2- 1984, published by the International Organizationforstandard- ization (ISO). The January 1972 edition of this standard forms the basis of numerous other parts of DIN 45 635 dealing with specific fami- lie
4、s of machines. These parts retain their validity except when superseded by revised editions. Supplement 3 to DIN 45 635 contains a list of the families of machines already covered. Contents Page 1 Scope and field of application 4 2 Designation . 5 3 Terminology, quantities 5 4 Instrumentation . 9 5
5、Object under test and test conditions . 9 5.1 Object under test . 9 5.2 Operating condition of the machine 10 5.3 Installation and attachment of the machine . 10 5.4 Reference box, measurement surface, measurement distance, measuring points, measurement paths . 5.5 Test environment . 12 6 Test proce
6、dure 12 6.1 Measuring the A-weighted sound pressure level. 14 6.2 Measuring the sound pressure spectrum . 15 6.3 Measuring the background noise level . 15 6.4 Determining the area S of the measurement surface and the measurement surface ratio Ls . . 15 7 Evaluation . 15 7.1 Calculating the surface s
7、ound pressure level one-third octave band filter complying with DIN 4565 Filter Checking of instrumentation 4 By means of acoustic calibrator complying with DIN 45 656 *) before and after each test series; sound level meter to be verified for compliance with standard at maximum interval of 2 years (
8、unless subject to mandatory verification) I *) At present at the stage of draft. Page 4 DIN 45635 Part 1 Table 1 c. Noise emission parameters and application of data with regard to the 3 grades of accuracy Clause Noise emission parameters Grade 1 accuracy Grade 2 accuracy Grade 3 accuracy Aweighted
9、sound power level LWA Sound power spectrum Lw OCt or Lw ah oct 3.19 6.2 7.3 3.19 6.2 7.3 3.16 6.1.1 Sound pressure spectrum at operatols position or at loudest position Emission value related to operators position Determinable Deteminable Determinable Determinable Determinable Determinable Determina
10、ble Determinable Determinable Impulsive noise content A LI at operators position or at loudest position Determinable Tonal content Determinable Directivity index DI 3.18, 7.3 3.20,7.3 Appendix C Level variation with time Generally only subjectively determinable Determinable Only determinable with (h
11、emi-) Only determinable with (hemi-) , spherical measurement surface spherical measurement surface Comparison of machines of the same family or of different families 1.3 1 Comparison with specified values (e.g. with limiting values, labelled values, contractually agreed values) Determinable Determin
12、able Determinable Metrological basis for noise abatement measures Determining emission parameters of reference sound sources Acoustic planning tasks (e.g. including noise immission estimates) Suitable Suitable Less suitable, but applicable if grade 2 accuracy not attainable Less suitable, but applic
13、able if grade 2 accuracy not attainable 3.2 7.2 1 Determinable in every case Suitable, Suitable Less suitable but requiring much effort I Determinable in every case Determinable in every case 7.3 Appendix O 1 3.17 6.1.2 7.3 Determinable 1 Suitable, but requiring much effort but requiring much effort
14、 1 1 Suitable Suitable Less suitable 1 1 Suitable I Less suitable I Not suitable 1 Scope and field of application This standard is applicable to industrial noise sources such as equipment, machines, machine components, sub- assemblies and plant, which are referred to in thisstandard as machines. It
15、does not apply to vehicles for transporting persons and goods on public roads. It is applicable in cer- tain circumstances to industrial noise sources constituting a unit together with a vehicle. This standard established the basis for determining the noise (noise emission, airborne noise emission)
16、radiated by machines direct to the surrounding air by standard methods, so that the results are comparable (see Supple- ment 2 of DIN 45635for explanations relating to the noise emission parameters). Noise measurements on machines may serve various pur- poses (see table IC), e.g. comparison of the n
17、oise emission of machines of identical or differing family, comparison with specified emission values (e.g. limiting values, labelled values or agreed values), implementation of noise abate- ment measures or estimation of noise immission (see Sup- plement 2 of DIN 45635). The principal noise emissio
18、n parameter is the sound power level. The sound power level of a machine is a measure of the sound power radiated by the machine; for this purpose, the sound power is the sound energy passing in unit time through a surface enveloping the machine. The sound energy related to 1 s is designated as the
19、sound power of an isolated noise event (see subclauses 3.1.4 and 7.2). This standard describes the basic method for determining the sound power level of a machine with the aid of the envel- oping surface method. Other basic methods (reverberation room method, in-duct method) are described in DIN 45
20、635 Part 2 and Part 3 (at present at the stage of draft) and in DIN45635Part9(at present atthestageof draft). Intheenvel- oping surface method, measuring points are locaied on the enveloping surface (measurement surface) and the sound pressure levelsare measuredat these pointswhere theradiat- ed sou
21、nd power passes through. From these sound pres- sure levels with the necessary corrections made (pri- DIN 45635 Part 1 Page 5 marilyfor mathematically eliminating the influence of back- ground noise and reflections from the environment) and from the area of the measurement surface the sound power le
22、vel is calculated. For determining partial sound power levels (by means of parts of the enveloping surface) this standard shall be applied as appropriate (see also Appen- dix F and if necessary DIN 45635 Part 9, at present at the stage of draft). In addition to the enveloping surface method for dete
23、rmin- ing the sound power level, this standard also describes methods of determining further noise emission parameters (emission value related to operator?s position, impulsive noise content, noise spectrum and others) (see table IC). The measurement method is divided into three grades, according to
24、 accuracy. Of these grades of accuracy, grade 2 will be the one normally applicable. If the test conditions are too unfavourable for it, grade 3 accuracy shall be applied. Under exceptionally favourable conditions, as in laboratories, grade 1 accuracy may be adopted for maxi- mum accuracy. Table 1 g
25、ives a survey of the features and criteria of the three grades of accuracy. Reference is made to this each time in the relevant subclauses of this standard. The grades of accuracy and the information on the preci- sion of the method (see clause 8) relate in this standard to the determining of the so
26、und power level. For other noise emission parameters the grade indicated is only for guid- ance. When selecting the grade of accuracy consideration should be given not only to the acoustic conditions, but also to the dispersion of the noise emission of the machine (e.g. when reproducing the operatin
27、g conditions). If this dispersion is so great that the uncertainty of the test results (see clause 8) significantly depends on it, it may be desirable to lower the demands made on the acoustic test conditions accord- ingly, because of their diminished influence on the uncer- tainty of the test resul
28、ts, in otherwords to choose the lower- accuracy grade. As an alternative to this, the Part of DIN 45635 dealing with an individual family of machines may specify that instead of one measurement several meas- urements shall be made in order to reduce the uncertainty of the final result (see subclause
29、 8.2). A given grade of accuracy is deemed to be complied with if the requirements for this grade or for a higher grade of accuracy are met. Since this .standard lays down the general acoustic prin- ciples for noise emission measurement on machines of dif- ferent families in the context of a basic m
30、ethod without, however, being able to concern itself with the conditions applicable to the individual family of machines (in particular the operating conditions) provisions relating to this are spe- cified in the Parts (multi-digit Parts) of DIN 45635 dealing with the individual families of machines
31、 which, however, are not intended to be contradictory to this standard. Where such a Part does not (yet) exist, the direct application of this standard is possible in cases in which the basic principlesof this standard, particularly with regard to clause 5, are suffi- cient for obtaining results ful
32、filling the purpose of the meas- urement concerned. Parts of this standard series dealing with the individual fami- lies of machines generally give details on the following points, whilst relevant clauses of the present standard are simply referred to (the exception being the verbatim quot- ing of a
33、n international standard dealing with an individual family of machines): - the grade(s) of accuracy specified for the individual fam- ily of machines with regard to the method of measure- ment used and the acoustical characteristics of the machines; - noise emission parameters to be determined addit
34、ion- ally to the A-weighted sound power level; - specifications relating to the individual family of machines regarding scope and field of application, object under test, mounting and operating conditions, arrangement of measuring points, precision of method, test report, report on results. Appendix
35、 E makes it possible to specify, for the individual family of machines, simple test methods for inspection pur- poses. 2 Designation The method shall be designated giving the grade of accu- racy used. The designation shall include the term ?noise measurement?, the DIN number and the grade of accurac
36、y (KL) used, 1,2 or 3. Example: The method of noise measurement as specified in this stand- ard (01) for grade 2 accuracy (KL2) shall be designated: Noise measurement DIN 45 635 - O1 - KL 2 In Parts of DIN 45635 dealing with the individual families of machines the number of grades of accuracy may be
37、 re- stricted. The designation in these Parts is specified accordingly. If,. however,such Parts allow the use of several basic methods (e.g. reverberation room method as specified in DIN 45635 Part 2), the Part number XX is followed by the number of the Part of the basic standard applied (example: n
38、oise meas- urement DIN 45635-XX-O1 -KL2). If the noisemeasure- ment can only be uniquely defined by quoting the relevant appendix of the specialized standard, the capital letter sym- bol (e.g. B) denoting the appendix shall be additionallyquot- ed behind the Pari number XX (example: noise measure- m
39、ent DIN 45635 - XX - B - KL3). 3 Terminology, quantities See Appendix I for a survey of the principal symbols used. 3.1 Sound pressure level L, 3.1.1 The sound pressure level L, isgiven by the equation (1) P2 P PO Po L,= 1Olg - dB = 20 Lg -dB where p is the sound pressure; PO = 20 pPa is the referen
40、ce sound pressure. 3.1.2 The frequencyweighting or width of a restricted fre- quency band and the time weighting (S, F or i; see DIN IEC 651) shall be stated, for example, as follows: - A-weighted sound pressure level: LpA; - octave band sound pressure level: Lpoct; - one-third octave band sound pre
41、ssure level: Lp,h,ct; - A-weighted sound pressure level measured with time weighting S: LpAS (AS-weighted sound pressure level); - ?A-weighted sound pressure level measured with time weighting I: LpAI (Al-weighted sound pressure level, A- weighted impulse sound pressure level). 3.1.3 The time-averag
42、ed sound pressure level (averaged overthe specified time interval T) as laid down in DIN 45641 is denoted by the subscript ?m? and termed ?avera,ged level? with L, (t) in dB. Example: Lp I m. Page 6 DIN 45 635 Part 1 In the case of time weightings S and F the subscript “eq” (from “equivalent continu
43、ous sound pressure level”) is used instead of the subscripts “Sm” or “Fm”, since the following generally apply (see DIN 45645 Part 1): LpSm =Lpm =Lpeq LpASm = LpAFm = LpAeq LpoctSm =LpoctFm =Lpocteq Lp 1hoctSm = Lp oct Fm = Lp hocteq Note 1. The subscript “eq” in the present standard refers solely t
44、o the energy equivalence and is not to be understood as a reference to a noise immission measurement, e.g. as specified in DIN 45 645 Part 2. The time interval Tcan be indicated by an additional subscript: Lpeq,. Note 2. The averaging specified in DIN 45641 is also termed “energy averaging”. Note 3.
45、 If it is important to denote the time interval over which the averaging is made, this can be done by the use of an additional subscript T: Lpm,T. 3.1.4 The single-event sound pressure level for an isolat- ed single sound event of specified duration T(or specified measuring time ) IS the time-averag
46、ed A-weighted sound pressure level related to 1 s T 1s Note. For determining the single-event sound pressure level in frequency bands, the symbols Lpoct,ls or L, tho - octave band sound power level: Lwoct; - one-third octave band sound power level: LW The single-event sound power level LW, is found
47、with equation (3) by substituting as sound power P the sound energy of an isolated single sound event related to 1 s. In the context of the enveloping surface method the sound power level is calculated from the surface sound pressure level and the measurement surface ratio (direct method). The sound
48、 power of the machine under test can also be cal- culated by the so-called comparison method by comparing the sound pressure levels generated by the machine under test with those produced by a reference sound source of known sound power at the same place of installation (see subclause 3.14, second p
49、aragraph). is the sound power (sound energy radiated by the machine in unit time); 3.3 Enveloping surface method The enveloping surface method is a noise measurement method for determining the sound power (airborne sound emission) radiated by a machine into the surrounding air with the aid of sound pressure level measurements on the enveloping surface which surrounds the machine and through which the radiated sound power passes. This is conditional on the square of the sound pressure averaged over the enveloping surface and time being directly propor- tional to the radiat
