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Petersen-An Overview of Standards for Sound Power Determination | Sound | Noise
Description: sound noise in dwellings
sound noise in dwellings
by Erik Cietus Petersen, Bruel&Kjser, Denmark
In Europe, a new "Machinery DirecA tive" has been written, coming into force from 1/1/95 (see Appendix C). The purpose of this directive is to ensure the health of people using machines. The directive states, among other things, that equipment sold in Europe must fulfil specified noise demands. The equipment covered by this direc­ tive is everything from jacks and gar­ den tractors, to chain saws and plastic moulding machines. What should be stated in the in­ struction manual for the equipment? If the A-weighted sound pressure level is below 70 dB(A), this must be indicated (L <70dB(A) re 20 Pa). Above 70 dB(A), the A-weighted sound pressure level should be stated. If the sound pressure level exceeds 85dB(A), the A-weighted sound power level should also be stated. If the machine is very large, the sound power level is replaced by the sound pressure level measured at sig­ nificant positions. If the noise contains peaks exceed-ion_m/m ±u■ ± 1 x, 4 -±A ing 130dB(C), this must also be stated. AT *. i.i J. n J i i Note that all sound pressure levels should be measured under "free field" conditions at the position of the oper­ ators head. If that is not denned, the sound pressure level must be measured at a distance of 1 metre from the
,, .. , p T,. , Ti _._n 7 . 7 . , 0 Measurement using Bruel&Kjser bound rower Program lype 7679, which guides the , \ * *u jortaai^ o j i 7 +z, r + user through the measurement according s to to the ISO 9614-2 standard
some of t h e E u r o p e a n "Council Directives". ° three m a i n rou s: B a s i c g P standards for performing t h e sound power det e r m i n a t i o n , e n v i r o n m e n t t e s t standa r d s which describe t h e operation conditions u n d e r which t h e sound p o w e r determination should b e per. formed, a n d finally t h e s t a n d a r d s which describe i n s t r u m e n t a t i o n to be used Except for t h e e n v i r o n m e n t s t a n d a r d s w h e r e a lot of different s t a n d a r d s a n d council directives exi s t s a l l t h e i m p o r t a n t s t a n d a r d s for sound power d e t e r m i n a t i o n are covered by t h i s application note. N o t e : As a cross reference, Appendix A gives a list of t h e suggested i n s t r u m e n t a t i o n for different m e t h ods of sound power d e t e r m i n a t i o n , a n d Appendix B lists all t h e standa r d s covered in t h i s application note.
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This application note is a n introduction to t h e large n u m b e r of international s t a n d a r d s existing regarding sound power determination. T h e s t a n d a r d s mentioned are mainly ISO (International Organization for Standardization), IEC (International Electrotechnical Commission), ECMA (European Computer Manufacturers Association), DIN (Deutsches I n s t i t u t for N o r m u n g e.V.), ANSI (American National Standards Institute) a n d
The r e a s o n for s t a t i n g t h e sound power is not only because legislation d e m a n d s it, - i t is customer driven. r a n F° increasing n u m b e r of customers s ' it i i m p o r t a n t to e v a l u a t e differe n t products' noise specifications before they buy. Note t h a t for most m a n u f a c t u r e r s it is i m p o r t a n t t h a t their m e a s u r e m e n t s a r e m a d e according to a n i n t e r n a t i o n a l s t a n d a r d . This gives a form of security, otherwise they m i g h t l a t e r be held responsible for t h e i r noise specifications by c o n s u m e r organizations all over t h e world.
j is then calculated from the sound simple to calculate the sound power of the sound source under investigap r e s s u r e measurements and a knowlenvironment. the sound pressure level .What to measure? In the past. together with a J • J. and P r e s s u r e Measurements a free sound field or a free sound field . I h e relationship between sound power and sound pressure is similar. b u t with more complicated noise problems. such as sound level meters. What equipment should be used? That depends on the method chosen.g g o y e r n e d T M g method b y o v e r a reflecting plane. i i ^J ^ ^ J • i ^ i i. There are two different chamber... 1 and 2). ment it is in. n . same power. and whether other sources of heat are present For the same electrical power input. source operating (see Fig. as produced ISO 3741-47. What we hear is sound pressure but it is caused by the sound power emitted from the source. 2 Coaxial circular paths for microphone traverses ment. was what people were used to measunng. I h e sound power of the source er and sound pressure.T_ ^ •r ^u n r J> * used m the tree or semi-rree field. power is the cause. as produced by a reverberation room. produced by a sound source [Watt]. the use of sound power has become more and more popular Sound power is the acoustical energy per time unit. respectively methods for sound power determinaThe principle of the comparison tion based on pressure measuremethod is that the sound source un­ ments. a correcsince a relationship exists (the acousf r t h e *<>* ° n background noise is tic environment) between sound powmade. It is important to keep in mind that sound power determination also in­ cludes the operational conditions of the noise source. . How should the measurement be made? The sound power can be determined from sound pressure measurements. known reference sound source (see sound T h e p r i n d p l e o ft h e d i r e c t m e t h o d Fig 9) First? t h e reference source is turned on and the spatially i g ^ ^ t j i e s o u n d s o u r c e u n d e r investigation is placed in a known acoustic averaged sound pressure level is environment and then measurements measured (see Fig. a amuse sound field. Unfortunately the room has an influ­ ence which affects the measurement. Then the refof the spatially averaged sound preserence sound source is interchanged sure level are made with the sound with the source under investigation. . under which the sound power is going to be deter­ mined. .V types of acoustic environment a r e ed r SUch ™ /° determination. t h e heater radiates t h e -. and then the total cost easily overj M . * . 2 . Sound pressure is the effect. A sound source radiates power and . ~ . the insulation.. An electric heater radiates heat into a room and temperature is the effect. Once again the spatially averaged The background noise is also meassound pressure level is measured and ured. whether it is based on pressure or intensity.31-36 and by a n anechoic or semi-anechoic DIN 45 635. namely. it is now very . and where necessary. The temperature in the room is obviously dependent on the room itself. T o J this creates sound pressure. This method has the advantage that the room and station­ ary neighbouring sound sources the­ oretically do not influence the sound power determination. . Consider the following analogy.. . . but it may require special rooms to obtain a sufficient accuracy. ANSIS12. the direct method and the der investigation is placed in a C0 n m ™P™ ethod known acoustic environment (diffuse -I he direct method is primarily sound field only). XL. 3). . no matter what environ. is inex­ pensive. Sound . edge of t h e acoustic Determination ofSound P o w e r b a s e d OH S o u n d r w0 ^ Fig A Microphone positions on equal areas on the surface of a hemisphere Fig. Pressure based equipment. tion. . The sound power can also be deter­ mined from sound intensity measure­ ments.
I^v = L p + ( L w r e f . n .„ Reverberant Room Steady. .31/32. freq A-weighted and A-weighted in octave bands in ~^T^TA ISO 3744 ISO ISO 3745 3745 Precision Precision Outdoors or in in |large a r g e rroom oom Anechoic Anechoic or or semi-anechoic semi-anechoic room ^ „t..30 gives a very good 6 i n / ISO 3741 IS03741 ISO 3742 ISO 3742 . see ISO 3743/ANSI S12. Note. If the correction factor is unknown. ■ i i h ■ ■ i ■ i ■ ■ ■ ■ i ■ IM ■ ■ ■ ■ i ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ H ^ ^ ^ ^ ^ ^ ^ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^™ ^ . Sound power levels levels obtainable on. M . Precision Methods of Sound Power Determination in a „ .2.' band band Steady discrete Steady discrete frequency frequency or narrow-band narrow-band .1.31. ANSI S12. . Instrumentation: N in appendix A A-weighted A-weighted and i in n o one n e o or r t hthird ird octave bands " . " Any Any Precision methods (grade 1) of sound power determination in a reverberation room are governed by the standards ISO 3741.. The difference between them being ISO 3741 and ANSI S12. 3 The parallelepiped or "shoebox" measuring surface used in ISO 3744 curacy a n d with respect to ISO 3741/42 ^ ^ S 1 231/32 Like IbO 3741/42 IbO 3743 and ANSI S12. In the direct method. . while ISO 3742. broad­ broadband. . . ANSI S12. ANSI S12. narrownarrow­ band discretediscretefreq.31-36 standards.31/32.T n ^ of the room.i T i • . . Further the reverberation time of the room is characterised as a single number (the so-called nominal rever­ beration time of t h e room.33 gives reduced ac- Fig. the sound power is calculated from the spatially averaged source. . . " Reverberation Reverberation . I n these standards. t h e background noise measurements and the physical parameters of the room (volume. l-i broad-band noise sources. M w^r^^^r^^^^^^^^^^^^ ni A/TafVinrl -Ulieci ivieiiioa ISO 3743 1S03743 Engineering Engineering Special reverberation reverberation test room 1. . i . . .A/ AMOTomoA • J 3740 / A N S I S12. sur­ face area and reverberation time). ^Vab|e movable I I I 1. M . DIN45635-3 and ANSI S12. Instrumentation: N in appendix A l * 3 .L p r e f ) International International Standard Standard Classification Classification of of method method D Test environment environment Character of of Character noise Ct As an introduction to the ISO 374147 / ANSI S12. The direct method of ISO 3743 and ANSl S12.. r a t h e r than being variable with frequency.33 for details). . i ir method and a comparison method tor determination of sound power. narrownarrow­ source under band or band or source under discrete-freq test not discrete-freq. .. In the standards two meth­ ods are described. . . band.1. ISO overview of the various methods (see Table 1). broad­ No special test broadenvironment. ISO 3742.33 i s simplified with regpect t o ^ direct method o f T g 0 ^ ^ ^ ^ m ^ S12. In one In one or third .33. however. t h a t ISO 3743/ANSI S12. octave bands. broad­ broad. ■ ■ ■ ■ ■ 1 ii ■■ i i u u ■ ■ _. octave Optional: Optional" A-weighted A-weighted t^^^L^mmi^ ■■■■■■■IIMIIMM. T~ 1S03746 ISO 3746 I SO 3747 IS03747 Survey No special test environment A-weighted I Table 1 I — Steady. t h e re­ quirements for t h e reverberation room are "relaxed" with respect to ISO 3741/42 a n d ANSI S12. .T .1.onQ7/M Precision Precision . a reference sound source can be used to determine the acoustic properties „ in . t h e direct method and the comparison method. The measurement methods of ISO 3741 and ISO 3742 are the same.33 describe both a direct . .32 and DIN 45 635-2 a r e for narrow-band noise sources and place more stringent requirements on the characteristics of the room. r o o m room meeting meeting specified specified requirements requirements —— Steady. Engineering Methods of Sound Power Determination in a Reverberation Room The engineering methods (grade 2) of sound power determination in a re­ verberation room a r e governed by ISO 3743.32 and DIN 45 635-2.31 are for i i ! ! . Note t h a t t h e reference sound source can be used to determine the acoustic properties of the room.
. narrow-band or discrete tones.31/32. it is possible to determine t h e sound power from t h e unknown sound source.35. ISO 3742. the infaience of the environment on the determination is measured using a reference sound source. Instrumentation: J.2. D I N 4 5 635-3 and ANSI S12.1. The Aweighted sound power level is calcu­ lated from the measured values. L. For ISO 3744 the Reference Sound So urcc Type 4204 is used.2. In the standards two meth°ds are described. ISO 3743 and ANSI S12.2. This is a relaxation of ISO 3745 and ANSI S12. 7 . . to determine the correction factor for the room A _. Ine lype /b80 rrogram supports the comparison method in the reverberant field according to ISO method in almost-free-field conditions according to ISO 3744.35 (hence reduced accuracy). Note t h e existence of a similar standard (draft) ISO 3748. the spatially averaged sound pressure in the re- verberation room is measured with the reference sound source operating.33 gives reduced accuracy with respect to ISO 3741/42 and ANSI S12. n i order to obtain the room correction factor. the method is identical to ISO 3745 or ANSI S12.3 5 cannot.33 for details).33 are similar to ISO 3741/42 in t h a t they describe both a direct method and a 1. ANSI S12. 3 1 . rather t h a n being variable with frequency. Instrumentation: O in appendix A # Comparison Method 2.31. Engineering Method of Sound Power Determination in an Almostfree-field over a Reflecting Plane The engineering method of sound power determination in a n almostfree-field is governed by ISO 3744. M in appendix A 2.2. 4). the direct method and the comparison method. .1. or on a hemispherical measurement surface if the noise source is mounted on a reflecting plane (semi-anechoic chamber). ANSI S12. while ISO 3742. and the measurement surface can be either a hemisphere or a "shoebox".4 Complete system for sound power determination. In the comparison method.1. Otherwise. First. ISO 3743/ANSI S12. since they require too much effort.32 a n d DIN 45 635-2.31/32. Instrumentation: L in appendix A 1. M in appen­ dix A not. Engineering Methods of Sound Power Determination in a Reverberation Room The engineering methods (grade 2) of sound power determination in a reverberation room are governed by ISO 3743. the reverberation time of the room is characterised as a single number (the so-called nominal reverberation time of the room. Type 4204 (see Fig. K.2.3. or "shoebox". ANSI S12.32 and DIN 45 635-2 are for narrow-band noise sources and place more stringent requirements on the characteristics of the room. i special t e s t e n v i r o n m e n t a n d t h e m e t h o d s specified m ISO 3 7 4 1 . in t h a t it allows some deviations from true free-field conditions and the use of measurement surfaces other t h a n the sphere and hemisphere.35 and DIN 45 635-1. or s h o u l d rig. the requirements for t h e reverberation room are "relaxed" with respect to ISO 3741/42 a n d ANSI S12. ANSI S12. The source noise can then be measured in the same way by replacing the reference with the unknown sound source. The noise source can emit any kind of noise: broad-band.g. be applied. This is done at a number of microphone positions on a spherical measurement surface around the noise source under investigation (anechoic chamber). Based on the sound power values from the calibration chart for the reference source. Instrumentation: K. Survey Method of Sound Power Determination in an Almostfree-field over a Reflecting Plane The survey method (grade 3) of sound power determination in a n almostfree-field is governed by ISO 3746. I n these standards. It requires measurement of the operating noise source and the background noise. see ISO 3743/ANSI S12. If the acoustic properties of the room are unknown.36 and DIN 45 635-1. Precision Method of Sound Power Determination in an Anechoic or Semi-anechoic Chamber The precision method of determination of sound power in an anechoic or semi-anechoic chamber is governed by ISO 3745.31 are r f ° broad-banded noise sources. ANSI S12. .33. The measurement methods of ISO 3741 and ISO 3742 are the same. a reference sound source can be used to determine the correction factor.. e.34 and DIN 45 635-1. and the two spatially averaged sound pressure level spectra.4 5 and A N S I S 1 2 . This method can be applied in situ to sources which cannot be moved to a _. One such measurement surface is the parallelepiped. Further.1. m7 _ „0rt _ > 4 .1. Precision Methods of Sound Power Determination in a Reverberant Room Precision methods (grade 1) of sound power determination in a reverberation room are governed by the standards ISO 3741. These standards specify a survey method for measuring t h e overall weighted sound pressure levels a t prescribed microphone positions around t h e noise source. The difference between them being t h a t ISO 3741 and ANSI S12. . which has never been finally approved (1994). ANSI S12. However.
There are no restrictions on the test environment or the shape and size of the source.3. 5) which is placed in the immediate vicinity of the source under test.6 Measuring sound power in-situ using Sound Power Program Type 5304. broad-band. The comparison method described in ISO 3743 and ANSI S12. Instrumentation: P. 1 and 3). The noise emitted must be steady. the comparison method takes it into account. These standards specify a meth­ od for measuring the component of sound intensity normal to a measure­ ment surface (see Fig.21 and NF S31100. 6). It is not always simple to deter. representing a small partial area. M in appendix A 2. ! • mine the magnitude 01 the environ­ mental correction necessary however. ANSI S12. l h e method is applicable to any source for which a physically stationary measurement Fig. and the direct method ln f ee or J 1 almost-free-field conditions according to ISO 3744/45.comparison method for determina­ tion of sound power. Each point is located on the measure­ ment surface. Sound Intensity Probe Type 3548 and Sound Intensity Calibrator Type 3541 5 . Instrumentation: K. thirdoctave or band-limited A-weighted sound power level is calculated from the measured values. The Type 7680 Program supports the comparison method in the reverberant field according to ISO 3741143. The octave. the in­ tensity probe will be placed at a number of points (see Fig. narrow­ band or contain discrete frequencies. A reference sound source is used (see Fig. Survey Method of Sound Power Determination using a Reference Sound Source The survey method of sound power determination in accordance with the comparison method is governed by ISO 3747.33 is iden­ tical to the comparison method of ISO 3741/42 and ANSI S12. Type 4204 is riot required when measuring according to lb(J 3/4b Determination of Sound Power based on Sound Intensity Measurements according to the Point Method This method is governed by ISO 9614-1. in which the intensity flow is constant. The surface is chosen so as to enclose the noise source(s) of which the sound power level is to be determined. Q in appendix A Fig.1. .31/32.I P . Dual Channel Real-time Frequency Analyzer Type 2144. 5 Complete system for sound power determination. During the sound power determination. The standard describes the procedure to be used for determining the overall A-weighted sound power levels of machines and equipment which cannot be moved from their in­ stalled locations for acoustical testing purposes.
ANSI S12.K>.12.f^^^^\^ '"C""'' f/in\"""'-Yi\X^SEE&K Personal Computer Sound Power Program 5304and7679 rt 2144 ^PI^^^F^TI : l!^^^M.21 \\L standards support precision and engineering grades. To simplify the me­ chanical movement (the scanning). here by. The source is denned by the choice of measurement surface.9 Reference Sound Source Type 4204 and Electroacoustic 4205 Calibrated Source Type . ECMA 160 and INSTA 121. third-octave or band-lim­ ited A-weighted sound power level is calculated from the measured values.. .. for octave a n d third-octave bands.-:[ll ^a^^^^ijl my / y . Fig. 3 ant A). 7 Complete system for sound power determination using sound intensity measureThe Windows™ based PC software Type 5304 and 7679 makes sound power ments. I h e French s t a n d a r d Nb bSl-Wi) is a simplified version of t h e I S O a n d A N S I s t a n d a r d s supporting precision and engineering grade only. These standards specify a method for measuring the "spatial averaged" component of sound inten­ sity.-. 2). The method is applicable in situ. The method is applicable to any source.w e i g h t e d only. and on which the noise generated by the source is sta­ tionary in time. only the A-weighted Sound Power Level. unless a c o m p u t e r is u s e d to perform all t h e | | L^^^^JT br^V /. for which a phys­ ically stationary measurement sur­ face can be defined. or in special purpose test environments. A number of checks (field indica­ tors) ensure the quality of the sound power contribution from each meas­ urement surface. the intensity probe traverses over the measurement sur­ face (see Fig.-. n vided into a number oi partial areas. quick and easy Determination of Sound Power based on Sound Intensity Measurements according to the Scan Method This method is governed by ISO 9614-2. or in special purpose test environments. ^^ [ tors) ensure the quality of the sound power contribution from e a c h m e a s urement point. The I S O 9614-1 a n d ANSI S12. Instrumentation: E. determination.. This makes the determination rather complicated.-. .^^ProbT^ Z$A& * ® -— Sound Intensity 1 calculations.. in situ. During the sound power de­ termination. a n d survey grade for overall A . according to ISO 9614 parts 1 and 2 (the point and scanning method). unless a computer i s u s e d to perform all t h e 6 ^ i n ^ directive. the measurement surface can be di.surface c a n b e defined a n d t h e noise generated by the source is stationary in time. I I Ipai . The surface is chosen so that it encloses the noise source(s) for which the sound power level is to be deter­ mined. This makes the de­ termination complicated. is of interest. G or I in appendix A nfi-3 WLM Calibrator 3541 94i?75e . normal to a measurement sur­ face. The octave. out the spectrum may give an idea of how to reduce the noise level ulfil he f£f^/ / t pig. . A number of c h e c k s (field i n d k a - I y*\ M># J0? ^m^ jsp Sound Real-time Frequency Analyzer .
ferred to as "Basic Standards" or iust B-Standards). This is to ensure an equal comparison between competitive products on the market. . The ISO 9614-2.21 and S12. 12 instrumentation standards describe the minimum demands for sound intensity probes and analyzers. ~. t h e r e a r e & n u m b e r governs the linear averaging. Class 1 is needed (described above) to chooge b e t w e e n (often re. H in appendix A The Nordic standard INSTA 121 is . the field indicators are not as complicated to fulfil as the ones needed for the point method. I E C 651 a n d ^gj g L 4 d e s C ribes « n o r m a l » exponential averaging a s o u n d level metei . This makes sound power determination simple to perform. the first edition was pub­ lished.. half-octave and third-octave band filters for analysis of sound and vibration. i j. ^ to m e a s u r e g o u n d p r e g _ g u r e i e v e i ^ m a d d i t i o n to sound intensity level. Operational Conditions * Choosing one of the above described standards is very often not enough.21 and S12.. A ll the sound power standards describe how to determine the sound power. Instrumentation: A.. • ments and sound power determmation are made in the same way but the field indicators are limited to a single test ol adequate mstrumentation capability. . In 1986 came a revised version of the ANSI stand­ ard. to perform (see Fig. • r i the determination of sound power in . «.12 precision and engineering measurements. ^ ^ mentg ^ r e q u i r e d to ^ gound intengit i n o c t a y e or third. depends on the a c o u s t i c environment and the equipm e n t availabie.12 and ECMA 160 standards support engineering grade for octave and thirdoctave bands.10 Set-up for sound power determination of a Nilfisk industrial vacuum cleaner (Courtesy of Fisker & Nielsen A/S) 7 . (See Fig. to facilitate the use of the field indicators described in ISO 9614/ANSI S12. Instrumentation: F. The definitions of the filter curves are the same. w h e r e I E C 8 0 4 to fulfil ISO 9614/ANSI S12.12. i i mi n -rf^. and engineering and survey grade for overall A-weighted only. Tolerances are also given.) For various types of equipment special standards exist. and ECMA standards.11 define the octave. describing the conditions under which the equipment should be tested. Fig. .. The proper sound powe r standard to choose. 10.. The tolerances outside the pass-band (filter skirts) were set high to make up for the analogue electron­ ics used at that time. In 1966. „ . The IEC/ANSI instrumentation standard describes two degrees of accuracy: class 1 and class 2. T o ^ n ^ i H/ATMOT accordance with ISO 9614/ANSI g l 2 2 1 & n d g l 2 1 £ T Q m e e t t h e re _ i r e m e n t of ^ s t m d a r d instm. C or D in appenrfiX o t h e r Standards To d e t e r m i n e the sound power level of & n o i g e gource. This makes the measurement much easier Note that IEC 225 is under revis i o n (1994) to adopt some of the tolerances from the 1986 ANSI SI. the spedfication of the overall A-weighted filter is probably the most important. T a k e for i n s t a n c e a c h a i n _ s a w .11 standard. They are very often referred to as Instruments used for Determination of Sound Power The sound power standards refer to a number of instrumentation stand­ ards governing sound intensity ana­ lyzers and intensity probes. The instrumentation standards specify standardized filter curves. This is to enSU re e aCC Ura f the m u * . where class 2 is intended for survey measurements. 8). but they do not say anything about the o p e r a t i o n a l conditions. Regarding sound power. .. I h e measure.n . AJNbl . IEC 225 and ANSI SI. making measurements less dependent on the chosen filter manufacture. measure­ ment and display set-up parameters and tolerances. precision method. even without a computer.. f ° + ^ ref ment ol sound intensity applied to >i i . THA AATOT a simplified version ol the ISO. ANSI S12..oc_ t ave bands.calculations. but the toler­ ances have been decreased. Due to the physical properties of the spatially averaged scanning. of different standards Note that a proposal was made in 1994 for the scanning method: Determination of sound power levels of noise sources using sound intensity. ISO 9614-3.. and optionally to provide ^ ^ A _ w e i M e ^ b a n d l e y e l s I t ig ^ ^ . . IEC 1043 and ANSI SI..
. .g. 8 guaranteed by the manufacturer of the lawnmower y. i ."Noise Test Codes" or just C-Standards. Since . n n ^^^„ ^ . many specific types ol machine. The standa r d describes the acoustic test facilities > instrumentation and procedures to b e used for Precision grade deters n a t i o n °{ ™ Power levels in octave or third-octave bands. This is recognizable in t h e way European standards u J j-i... The machinery directive. i i • -. calls for European Standards and for purely formal reasons. they will be verification of sound power levels of internationally approved a n d then hand-held chain-saws. made comparison of noise emission difficult. od for t h e measurement ol airborne . . . T I P coo on/oco 00/10A 0Q/1O1 11 • termming b the sound power level ol 538. .-. It is based on the use of ISO 3741/42. 15 . Preferred A careful examination of all existmethods for determination of sound ower levels ing C-Standards is beyond t h e scope P according to this standof this application note.T i IA T C ^ c n . . T h e measurements are made under d i f f l l s e field c o n d i t i 0 n s . and octave band sound pressure lev1957 several European committees ■. . er cranes. The standard provides reierencetolawnmowers.■ n v borne sound insulation tor small elements.. hence. 12). . . of a noise source having a volume prefer. . ...11 chain-saws. in all t h e information necessary to In a couple or years(!) when the make. dampers and valves used in air diffusion and air distribution systems. standardization in acoustics has occurred internationally.. 88/180. number! Most of the specific C-Standards -HI • Air Terminals ISO 5135 defines requirements for acoustic testing in reverberation rooms of air terminal units. a wide variety of methods h a s been applied by individual manufactures and users to satisfy particular equipment or application needs. . . as examples: Sound Insulation Business Equipment ISO 7779/ECMA 74 specifies a meth-. r . mi ' ' o T^. used in forests (see Fig. . t h e reverberation room. T 7 M u • are numbered: t h e EN number is . . 14). Noise declaration ISO 4871 is a standard under revis ion (1994). / . The Nordtest standard is a simplified version of the ISO standard as it assumes t h a t there is no flanking transmission. *f. In order to ensure accuracy. . comcific safety standards: Council Direcb u g t i o n e n g i n e c h a i n _ s a w s for u s e tive 79/113 (year/number) EEC p r i m a r i l y i n f o r e s t s . i n A / ISO 9207 specifies a method tor deAf. 84/534 covers towtive ( s e e jgQ 9207). This standard. 84/535 and 85/407 refer to welding generators. _ els. i . . „ . measuring t h e overall A-weignted c 0. 87/252. noise emitted by computers and business equipment (Fig. .-. . however. 84/536 a n d 85/ . .. declaration and Standards is concluded.12 Measurement surface surrounding computer a personai ISO 140-10 and NORDTEST 1065-92 ^ T ^ f ° scanning method ol measuring air.a r 408 refer to power generators and 84/ .Seelig. nnnnn found by adding 20000 to the ISO . . . 88/181 are all in . . This standard applies to a broad range of machinery doeg n o t coyer gound p o w e r determi_ used m work on civil engineering and n a t i o n j therefore it is important to building sites. . • Chain-saws Fl §- n EEC Machine Directive Label in- dicating the maximum sound power level are at t h e moment European since I S 0 7 1 8 2 ifies a method for there are no ISO counterparts lor the . primarily only t h e ISO standards will exist. Traditionally. which applies to machinery and equipment: — gives information on the declaration of noise emission values Spedfy & S Und lntenSity ^ ^ MeasuremeM of sound power on a personal computer showing the intensity probe's path over the measurement surface . See 13 Fig. r . at the operator s position. Until now. in many cases.. . See Table 2. it h a s been necessary to establish a European committee. This standard simplifies such comparisons and is the basis for declaration of noise emission levels of computers and business equipment. t h e measurements made are simpler. .„. under standardized conditions. the standard is based on ISO 3741/42/44/45.il. 89/514 covers earthf u l f i l t h e European Machinery Direcmoving machines.ni .. European standardization work of Ct h e determination. b u t the folard are engineering methods (grade lowing standards are mentioned just '' tabled. . . They have decided to implement international standards in their original form. This method also huMmg e s t a b l i s h e s d i r e C t l o n S regarding rep o r t i n g a n d a p p l y i n g s u c h t e s t data. validlty and acceptability. ol noise have prepared a large number of speemitted b rtabl n a n d _ h e l d .. r.These diverse practices have. ^ -.^ r ^ i r in ably J less t h a n 1% ol the volume ol .
DIN45 635 DIN 45 635 is a German standard which contains several hundred parts. The values to be used for the declaration of noise emission are the overall A-weighted sound power level.J .0 B 0B 56 5 6 dB dB I Table 2 Example of declared 1 noise emission values from ECMA ECMA 1 Standard 1 stated by the manufacturer. L Lpm ' " dB dB pm in idlina Idling Full load load Full R .describes acoustical and product information to be stated in technical documents supplied to users by the manufacturer — specifies the method for verifying t h e declared n o i s e e m i s s i o n v a l u e s I Product: p ro duct: Declared L Computer Model Model ABC Computer ABC Noise Emission Emission [ Operating 7 1B 7.g. a complete system of standards is available which provide a basis for establishing a specific ma­ chine noise measurement (noise test code) for almost any situation. is called a noise test code. la­ belled) values of the noise emitted by machinery and equipment. ISO 9207 describes the measurement conditions and recommends the standard. From Beuth Verlag GmbH. I | | Table 3 Acoustical date to be reported according to ISO 9207 Fig. Part 1 to 3 are B-Standards w r i t t e n in l i n e w i t h t h e I S O 3 7 4 x family. Part 2 gives methods for stating values for the individual machines (manufac­ ture). at operator or bystander positions. Lw in dB dB L w in . Fig. and part 3 gives methods for verifying stated (labelled) values for batches of machines. and as they will be able to supply not only the international standards but also domestic standards. so numbers between 8 and 3400 are usual. : :. Together with ISO 3740-47 and ISO 11200-11204. 15 An example of Calibration m 942050e 9 . Berlin 30. according to which a measurement should be performed machinery. Operating condition condition Operating . The numbering is not con­ secutive. my ~ l l g L a ^ . b u t t h e r e s t are N o i s e Test C o d e s for v a r i o u s t y p e s of . it is possible to ob­ tain the parts of the standard. The declared values are the statistical upper limits corresponding to the stated or labelled value defined in ISO 7574. Racing . ISO 7574 part 1 and 4 define terms relating to methods for determining and verifying the stated (e. 14 Position of chain saw during measurement to ISO 9207.1 B I Idle 7 l-WAd wAd LpAm ■-PAm (bystander position) 57 5 7 dB dB - 7. s e e above. and the A-weighted emission sound pressure level.
Appendix A instrumentation A Type 3554 Sound Intensity System (contains Type 4437 + 3547 + 4231 + DP 0888 + WT9347 + WT9378) B Type 3562 Sound Power System (contains Type 2144 + 3548 + 3541 + 7679) C Type 3563 Sound Intensity Mapping System (contains Type 2133 + 3545 + ZH0354 + 3541) D Type 2144 Portable Real-time Frequency Analyzer Type 3548 Sound Intensity Probe Type 3541 Sound Intensity Calibrator E Type 3563 Sound Intensity Mapping System contains Type 2133 + 3545 + ZH0354 + 3541) Type WT9378 Mapping and Sound Power Program AO 0265 IEEE 488 Standard Digital Interface Cable PC with IEEE Interface running Windows™ F Type 3562 Sound Power System (contains Type 2144 + 3548 + 3541 + 7679) AO0265 IEEE 488 Standard Digital Interface Cable PC with IEEE G Type 3554 Sound Intensity System (contains Type 4437 + 3547 + 4231 + DP 0888 + WT9347 + WT9378) AO0265 IEEE 488 Standard Digital Interface Cable PC with IEEE interface running Windows™ H Type 3563 Sound Intensity Mapping System (contains Type 2133 + 3545 + ZH0354 + 3541) Type 7679 Sound Power Program AO0265 IEEE 488 Standard Digital Interface Cable PC with IEEE interface running Windows™ I As set-up F plus Type 5304 Sound Power Program 2 x AO 0265 IEEE 488 Standard Digital Interface Cable PC with IEEE interface running Windows™ M As set-up L plus Type 4204 Reference Sound Source N Type 2123/33 Real-time Octave and Fractional Octave Digital Frequency Analyzer Type 2669 B Falcon Microphone Preamplifier Type 4192 Falcon™ Condenser Microphone Cartridge Type 3923 Rotating Microph one Boom Type 4231 Sound Level Calibrator Type 4204 Reference Sound Source AQ0034 Remote Control Cable O Type 2236 Precision Integrating Sound Level Meter Type 4231 Sound Level Calibrator P As set-up O plus Type 4204 Reference Sound Source Q Type 2260 Investigator™ Modular Precision Sound Analyzer Type 4231 Sound Level Calibrator Type 4204 Reference Sound Source J Type 2143/44 Portable Real-time Frequency Analyzer Type 2669 B Falcon Microphone Preamplifier Type 4192 Falcon Condenser Microphone Cartridge Type 3923 Rotating Microphone Boom Type 4231 Sound Level Calibrator AO0265 IEEE 488 Standard Digital Interface Cable PC with IEEE interface running Windows™ K As set-up J plus Type 4204 Reference Sound Source L Type 2143/44 Portable Real-time Frequency Analyzer Type 2822 Microphone Multiplexer 10 x Type 2669 B Falcon™ Microphone Preamplifier 10 x Type 4192 Falcon™ Condenser Microphone Cartridge Type 4231 Sound Level Calibrator Type 7680 Sound Power Program AO0087 BNC Coaxial Cable 10 .
21 Similar to ISO 9614-1 NF S31-100 French standard.34.30 Revised version of ANSI S1.Scanning method for use in situ Instruments u s e d for Determination of Sound Power: IEC 651 Sound Level Meters ANSI S1. grade 1.Determination of sound power levels ISO 140-10 Measurement of sound insulation in buildings and of building elements .33 Revised version of ANSI S1. intensity scanning under laboratory conditions ISO 4871 Declaration and verification of noise emission values of machinery and equipment ISO 7574 Statistical methods for determining and verifying stated noise emission values of machinery and equipment (part 1-4) DIN 45 635 This German standard contains several hundred parts.Appendix B Determination of Sound P o w e r b a s e d on Sound Pressure Measurements: ISO 3740 Guidelines for the use of basic standards and for the preparation of noise test codes ISO 3741 Precision method for Broad-band sources in reverberation rooms ISO 3742 Precision method for discrete frequency and narrow band sources in reverberation rooms ISO 3743 Engineering methods for special reverberation test rooms ISO 3744 Engineering method for free-field conditions over a reflecting plane ISO 3745 Precision method for anechoic and semi-anechoic rooms ISO 3746 Survey method ISO 3747 Survey method using a reference sound source ANSI S12. Equivalent to ISO 3742 ANSI S12. Equivalent to ISO 3746 DIN 45 635-1 Similar to ISO 3744/45/46 DIN 45 635-2 Similar to ISO 3741/42 DIN 45 635-3 Similar to ISO 3743 Determination of Sound P o w e r based on Sound Intensity Measurements: According to the point method: ISO 9614-1 Determination of sound power levels of noise sources using sound intensity .32.11-1986 ANSI SI.32 Revised version of ANSI S1.Measurements by scanning.Measurements at discrete points. New version in 1986 Other Standards: ISO 7779/ECMA 74 Measurement of airborne noise emitted by computer and business equipment ISO 5135 Determination of sound power levels of noise from air terminal devices. grade 1 and 2 According to the scan method: ISO 9614-2 Determination of sound power levels of noise sources using sound intensity .averaging Sound Level Meters IEC 1043 Instruments for the measurement of sound intensity . Equivalent to ISO 3744 ANSI S12. grade 2 and 3 ANSI S12.Measurements with pairs of pressure sensing microphones ANSI SI. 2 and 3 ANSI S12.31 Revised version of ANSI S1.33.35. see above.35 Revised version of ANSI S1. Equivalent to ISO 3741 ANSI S12.Measurement of sound insulation of small building elements Nordtest 1065-92 Small building elements: Sound insulation. and under revision (1994) inspired by ANSI SI.11 1966 edition equivalent to IEC 225-1966.12 Equivalent to IEC 1043 IEC 225 Octave.31. dampers and valves by measurements in a reverberation room ISO 7182 Measurements at the operator's position of airborne noise emitted by chain saws ISO 9207 Manually portable chain-saws with internal combustion engine .4 Equivalent to IEC 651 IEC 804 Integrating .36 Revised version of ANSI S1.30.34 Revised version of ANSI S1. Equivalent to ISO 3740 ANSI S12. Equivalent to ISO 3745 ANSI S12. 1966. air terminal units.12 Similar to ISO 9614-2 ECDMA 160 Using computer equipment. similar to ISO 9614-2 INSTA 121 Determination of sound power levels of noise sources using sound intensity . Parts 1 to 3 are B-Standards. but parts 8 to 3400 (or higher) are Noise Test Codes for various types of machinery 11 . half-octave and third-octave band niters intended for the analysis of sound and vibration.36. Equivalent to ISO 3743 ANSI S12.
g. to be used by government au­ thorities giving uniformity in all EU member states. Therefore the direc­ tives do not give any technical solu­ tions. 93/44/EEC and 93/ 68/EEC. calculations. which can be bought either direct from the "Office for the EU official publications. This appendix gives a brief introduction to the contents of Machinery Directive 89/392/EEC and the updates 91/368/EEC. The manufacturer just has to state that used in a specified configuration. we recommend t h a t you obtain the com­ mended version of the directive. to be used by the same group of people in the same environment. EMC. As documentation. The safety of the operator is emphasized in a number of subjects. and the excep­ tions. Possibility of sanctions There has been a lot of talk about the risk of and government sanction against installing machines or equipment covered by the Machinery Directive which is not CE labelled. Note that Brtiel&KjaBr cannot be held responsible for any misinterpretati'on of the following text. Directives are updated by issuing new directives to be appended. only what is needed when selling a product. or from a local sup­ plier (more t h a n 30 countries all over the world). railways. As a guarantee t h a t the machine fulfils the directive. Furthermore. a new "Machinery Directive" has been written. but commonly they are written by engineers and technicians associated with industry or technical high schools. Standards Most engineers are familiar with standards. L-2985 Luxembourg" (price: ECU 15).and mains-supply directives. this directive calls on a number of other directives. and one of them is the contents of the instruction manual. The Directives are. it must be labelled with the "CE" mark. It is important to notice t h a t when a directive has been written. must be kept by the manufacturer.g. unless it is sold second-hand. Well. The purpose of this directive is to ensure quality and the health of people using machines and also to ensure free trade over the boarders. test results and product description. e. coming into force from 1/1/95. in the EU BO 0416-12 . it will never be changed. 16 A wide range of machinery must fulfil the "Machinery Directive" to be marked and sold. that the equipment is produced in harmony with the standards mentioned in the statement.Appendix C The Machinery Directive In Europe. the manufacturer has to state. e. Furthermore. ships. a technical dossier containing drawings. Standards can be international or domestic. For Briiel&KjaBr this is of interest because sound and vibration levels must be stated. airplanes and vehicles used for passenger transport. completely different. The di­ rective defines which machines and safety components it covers. the worst thing t h a t can happen is either t h a t government authorities closes down the factory until the illegal equipment is gone or that your insurance company will not cover the damages your illegal equipment may have caused! Fig. the complete assembly can be CE marked. They are written by law­ yers. Contents of the directive The Machinery Directive consists of 14 articles and 7 appendices. on the other hand. manufacturers are allowed to exhibit equipment which does not fulfil the directive if it is written on the machine. If a machine does not fulfil the requirements given by the directive. To fulfil the safety requirements. especially dangerous machines. Directives vs. Re­ garding the Machinery Directive. government authorities must prohibit the use of the machine in the EU country. Note that components for a larger machine do not need to be CE marked.
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