ANSI AMCA 320-2008 Laboratory Methods of Sound Testing of Fans Using Sound Intensity《使用声音强度进行风扇噪音测试的实验室方法》.pdf

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1、AIR MOVEMENT AND CONTROLASSOCIATION INTERNATIONAL, INC.30 West University DriveArlington Heights, IL 60004-1893 U.S.A.E-Mail : infoamca.org Web: www.amca.orgTel: (847) 394-0150 Fax: (847) 253-0088The Air Movement and Control Association International, Inc. is a not-for-profit international associati

2、on of the worlds manufacturers of related air system equipment, primarily, but not limited to: fans, louvers, dampers, air curtains, airflow measurement stations, acoustic attenuators, and other air system components for the industrial, commercial and residential markets.The International Authority

3、on Air System ComponentsAIR MOVEMENT AND CONTROLASSOCIATION INTERNATIONAL, INC.ANSI/AMCAStandard 320-08Laboratory Methods of Sound Testing of Fans Using Sound IntensityAn American National Standard Approved by ANSI on September 17, 2013(R2013)ANSI/AMCA STANDARD 320-08Laboratory Method of Sound Testi

4、ng of Fans Using Sound IntensityAir Movement and Control Association International, Inc.30 West University DriveArlington Heights, IL 60004-1893(R2013) 2013 by Air Movement and Control Association International, Inc.All rights reserved. Reproduction or translation of any part of this work beyond tha

5、t permitted by Sections 107 and108 of the United States Copyright Act without the permission of the copyright owner is unlawful. Requests forpermission or further information should be addressed to the Executive Director, Air Movement and ControlAssociation International, Inc. at 30 West University

6、Drive, Arlington Heights, IL 60004-1893 U.S.A.AuthorityANSI/AMCA Standard 320 was adopted by the membership of the Air Movement and Control Association International, Inc. on May 6, 2007. It was approved as an American National Standard on April 18, 2008. It was reaffirmed on September 17, 2013. AMC

7、A 320 Review CommitteeTim Mathson, Chair Greenheck Fan CorporationDr. John Cermak Acme Engineering Acoustical Society of America, 120 WallStreet, 32nd Floor, New York, 10005-3993 U.S.A. ANSI S12.5-1990 American National StandardRequirements for the Performance and Calibration ofReference Sound Sourc

8、es, Acoustical Society ofAmerica, 120 Wall Street, 32nd Floor, New York,10005-3993 U.S.A. (AMCA 1863-90-A0)ANSI S12.12-1992 American National StandardEngineering Method for the Determination of SoundPower Levels of Noise Sources Using SoundIntensity, Acoustical Society of America, 120 WallStreet, 32

9、nd Floor, New York, 10005-3993 U.S.A. (AMCA 1850-92-A0)ANSI S1.40-1984 (R1990), American NationalStandard Specification for Acoustical Calibrators,Acoustical Society of America, 120 Wall Street, 32ndFloor, New York, 10005-3993 U.S.A.(AMCA 1895-84-A0)ANSI/IEEE SI 10-1997 Standard for Use of theIntern

10、ational System of Units (SI): The Modern MetricSystem, Institute of Electrical and ElectronicsEngineers, 445 Hoes Lane, Piscataway, N.J., 08854-4141 USA 1ANSI S1.11 band number 18 21 24 27 30 33 36 39Nominal midband 63 125 250 500 1000 2000 4000 8000frequency (Hz)ANSI S1.11bandnumber1718192021 2 232

11、425262728Nominalmidbandfrequency(Hz)50 63 80 100 125 160 200 250 315 400 500 630ANSI S1.11bandnumber29 30 31 32 33 34 35 36 37 38 39 40Nominalmidbandfrequency(Hz)800 1000 1250 1600 2000 2500 3150 4000 5000 6300 8000 10,000Table 1A - ANSI S1.11 Octave BandsTable 1B - ANSI S1.11 One-Third Octave Bands

12、ANSI/AMCA 320-083. Definitions / Units of Measure / SymbolsThe acoustical definitions and symbols used in thisstandard are taken from appropriate ANSI standardswhenever possible; some have been expanded to fitthe specific needs of this standard. The non-acoustical terms and units used are defined in

13、ANSI/AMCA 210, and are consistent with those usedin ANSI/AMCA 300.3.1 Definitions3.1.1 Blade passage frequency (BPF). Thefrequency of fan impeller blades passing a singlefixed object, calculated by the following formula. 3.1.2 Decibel (dB). A dimensionless unit of level, inlogarithmic terms, for exp

14、ressing the ratio of a poweror power-like quantity to a similar reference quantity(see Sections 3.1.12, 3.1.13, and 3.1.14).3.1.3 Ducted fan. A fan having a duct connected toeither its inlet or outlet, or both.3.1.4 End reflection. A phenomenon which occurswhenever sound is transmitted across an abr

15、uptchange in area, such as at the end of a duct in aroom. When end reflection occurs at the end of aduct in a room, some of the sound is reflected backinto the duct and does not escape into the room.3.1.5 Frequency range of interest. For generalpurposes, the frequency range of interest includesthe o

16、ctave bands with mid-band frequencies from 63Hz to 8000 Hz; i.e., from the lower cut-off of the 63 Hzband to the upper cut-off of the 8000 Hz band.3.1.6 Informative. A term which indicates that thereference or annex is provided as advice to the userof this standard.3.1.7 Nonducted fan. A fan without

17、 ducts connectedto its inlet and outlet.3.1.8 Normative. A term which indicates that thereference or annex contains requirements which aremandatory in order to comply with this standard.3.1.9 Octave band. The interval between any twofrequencies having a frequency ratio of two. The fanindustry report

18、s sound power levels in eightstandardized octave bands which are shown in Table1A and Table 1B.3.1.10 Reference point of fan equipment. Theposition that is used to define and locate themeasurement surface relative to the fan equipmentunder test (see Figures 1, 2, 3 and 4). For fan inlet (orBPF =Numb

19、er of Blades Fan RPM60Hz2Table 2 - SymbolsUnless otherwise noted, subscript numbers refer to the AMCA Octave Band Number. The non-acoustical termsand units used are defined in ANSI/AMCA 210 and IEEE/ASTM SI 10-1997.Symbol Description SI Unit IP UnitAnArea of nthsegment m2ft2c Speed of sound m/s ft/s

20、ecd Characteristic acoustic source dimension m ftD Duct diameter m ftEiDuct inlet end correction dB dBEoDuct outlet end correction dB dBEwAdjustment to sound power level for duct end correction(s) dB dBf Frequency Hz HzI Sound intensity W/m2*I Sound intensity I at measurement location n W/m2*InSurfa

21、ce average sound intensity W/m2*IrefReference intensity, 1 pW/m2(1.0 10-12W/m2)-I Measurement surface characteristic dimension (length) m ftLISound intensity level (re. 1 pW/m2)dBdBLISurface average sound intensity level dB dBLIfFan sound intensity level dB dBLlfSurface average fan sound intensity l

22、evel dB dBLlqRSS sound intensity level dB dBLlqSurface average RSS sound intensity level dB dBLpSound pressure level (re. 20 Pa) dB dBLpbBackground sound pressure level dB dBLpbSurface average background sound pressure level dB dBLpbnLpbat measurement location n dB dBLWSound power level (re. 1 pW) d

23、B dBLWiFan inlet sound power level (ducted inlet) dB dBLWmFan total sound power level (non-ducted fan) dB dBLWmiFan inlet sound power level (non-ducted inlet) dB dBLWmoFan outlet sound power level (non-ducted outlet) dB dBLWoFan outlet sound power level (ducted outlet) dB dBLWqRSS calibration sound

24、power level dB dBp Sound pressure Pa *prefReference sound pressure, 20 Pa (2.0 10-5Pa) - -PsFan static pressure Pa in. wgPtFan total pressure Pa in. wgQ Fan airflow rate m3/s cfmr Measurement surface characteristic dimension (radius) m ftRWSound power level reference source adjustment dB dBS Surface

25、 area of measurement surface m2ft2SrefReference area, 1 m2- -W Sound power W *WrefReference sound power, 1 pW (1.0 10-12)-WNConvergence index (with N measurement locations) dB dBz Measurement surface characteristic dimension m ft(height above reflecting plane)* I-P units not usedANSI/AMCA 320-083out

26、let) sound power testing of equipment with a singleinlet (or single outlet), the reference point is the centerof that inlet (or outlet). For fan total sound power testingof equipment with a single inlet and a single outlet, thereference point is the midpoint of the line that joins thecenters of the

27、inlet and the outlet. Generally, thereference point is the centroid of the centers of all inletsand outlets that contribute to the sound power levelbeing determined. 3.1.11 Shall and should. The word shall is to beunderstood as mandatory; the word should as advisory.3.1.12 Sound intensity level, LI,

28、 in decibels. Tentimes the logarithm (base 10) of the ratio of absolutevalue (magnitude) of the sound intensity, I, to thereference intensity, Iref.3.1.13 Sound power level, LW, in decibels. Ten timesthe logarithm (base 10) of the ratio of the sound powerW to the reference power Wref. 3.1.14 Sound p

29、ressure level, Lp, in decibels. Tentimes the logarithm (base 10) of the square of the ratioof the sound pressure, p, to the reference pressure,pref. Unless otherwise stated, the sound pressure, p, isthe root-mean-square (rms) pressure. 3.2 SymbolsSee Table 2 (page 3).4. Instruments and Methods of Te

30、st4.1 Sound pressure microphonesPressure-sensing microphones shall comply with therequirements of ANSI S12.12.4.2 Sound intensity probesThe sound intensity probe shall consist of twopressure-sensing microphones, and comply with therequirements of ANSI S12.12.Note: To cover the entire frequency range

31、 of interest,it may be necessary to use more than one probe ormicrophone spacing.4.3 Frequency analyzerAn octave band or one-third octave band filter setshall meet or exceed the Order 3, Type 1-D,requirements of ANSI S1.11. 4.4 Reference sound source (RSS) The reference sound source should comply wi

32、th therequirements of ANSI S12.5.4.4.1 The RSS shall be a small, modified, direct-driven centrifugal fan having maximum overalldimensions of 610 mm (2 ft) or less.4.4.2 The RSS shall produce steady, broadbandsound over at least the frequency range from 50 Hzto 10,000 Hz. It shall comply in all respe

33、cts with theperformance requirements of ANSI S12.5 except forthe spectral characteristics of the 50 Hz and 10,000Hz one-third octave bands, where the sound powermay deviate by up to 6 dB from the sound level of theadjacent one-third octave band. The sound poweroutput shall be high enough so that the

34、 soundpressure and sound intensity levels shall be greaterthan the background noise levels. See Section 7.2.4.4.3 The RSS shall be equipped with vibrationisolators to minimize vibration transmission from theRSS into the structure of the room. The degree ofisolation should be 20 dB or more. If metal

35、springsare used as vibration isolators, rubber pads shall beused between the isolator and the structure of theroom.4.4.4 To ensure compliance with the stabilityrequirements of ANSI S12.5, all operating parts of theRSS shall be rigidly and permanently attached. Norubbing or wearing parts shall be per

36、mitted (exceptlubricated bearings) and protection shall be providedagainst corrosion.4.4.5 The RSS calibration shall consist of adetermination of the sound power level radiated bythe source when it is in operation on a reflectingplane with radiation into a free field above that plane.The calibration

37、 shall be in accordance with therequirements of ANSI S12.5, or as provided in AnnexF. The maximum time interval since calibration shallnot exceed that specified by the manufacturer, orthree years, whichever is shorter. Note: The RSS is used to qualify the performance ofthe sound intensity measuremen

38、t system andLppprefdB=10102logLWWWrefdB=1010logLlllrefdB=1010log4ANSI/AMCA 320-085personnel, and to determine a sound power leveladjustment for the specific site conditions. To be usedfor these purposes, the RSS must be of appropriatetype, be calibrated accurately and be properlymaintained.4.5 Frequ

39、ency response of instrumentationsystemThe frequency response of the instrumentationsystem shall be flat over the frequency range ofinterest within the tolerances given in Table 3, appliedas outlined in ANSI S12.12.Note 1: For sound intensity measurements, the useof two or more different configuratio

40、ns of the intensityprobe, or different probes, may be required to coverthe entire frequency range in conformance with Table3. Note 2: The useful frequency range for accuratesound intensity measurements is dependent uponthe character of the sound field. Care shall be takento verify that sound intensi

41、ty measurements areaccurate in the actual measurement environment.Table 3 - Tolerances for the InstrumentationSystem4.6 Transducer and instrumentation systemcalibration checks Before and after each series of sound powerdetermination the following calibration checks shallbe performed. A calibration c

42、heck of the entiremeasuring system at one or more frequencies withinthe frequency range of interest shall be made foreach microphone. An acoustical calibrator conformingto ANSI S1.40, and having an accuracy of 0.5 dB orbetter, shall be used for this purpose. In conformancewith ANSI S1.40, the calibr

43、ator shall be checked atleast once every year to verify that its output has notchanged. In addition, an electrical calibration of theinstrumentation system over the entire frequencyrange of interest shall be performed periodically, atintervals as recommended by the manufacturer(s),but not more than

44、two years.In addition to the calibration check, the field checkprocedure for sound intensity measurement specifiedby the manufacturer shall be performed. If no fieldcheck procedure is specified, the following procedureshall be performed:The intensity probe shall be placed at themeasurement surface,

45、oriented normal to thesurface, at a position where the noise ischaracteristic for the fan equipment under test. Thesound intensity shall be measured. The intensityprobe shall be rotated through 180 degrees andplaced with its acoustical center in the same positionas the initial measurement. The sound

46、 intensity shallbe measured again. The intensity probe should bemounted on a stand or other mechanical device sothat its acoustical center retains the same positionwhen the probe is rotated. For the octave band withthe highest level, the absolute difference between thetwo levels shall be less than t

47、he value in Table 4 forthe measuring equipment to be acceptable. The twosound intensities shall be of opposite sign.4.7 Performance verification Periodically, the performance of the instrumentationsystem shall be verified by determining the soundpower of a reference sound source using theprocedures

48、specified in ANSI S12.12. This verificationshall be performed monthly by qualified personnel(see Section 6.2) or at the time of soundmeasurements if this occurs at intervals greater thanone month apart.The sound power level determined for the referencesource shall differ from its calibrated value ov

49、er thefrequency range of interest by no more than thetolerance given in Table 5.Table 4 - Tolerance for Difference in SoundIntensity Levels for Field CheckTable 5 - Tolerance for Sound Power LevelDetermined for Reference Sound SourceOne-third Octave Band(Hz)Tolerance (dB)50-80100-40005000-800010,0001.51.01.52.0Octave Band (Hz) Tolerance (dB)63125250-5001000-400080005.03.02.01.52.5Octave Band (Hz) Difference (dB)63-125250-400080001.51.01.5ANSI/AMCA 320-08ANSI/AMCA 320-084.8 Test methodThe basis of the test method originates in ANSIS12.12. The te