1、Designation: F2544 11An American National StandardStandard Test Method forDetermining A-Weighted Sound Power Level of CentralVacuum Power Units1This standard is issued under the fixed designation F2544; the number immediately following the designation indicates the year oforiginal adoption or, in th
2、e case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method calculates the overall A-weightedsound power level emitted by central
3、 vacuum power units,intended for operation in domestic applications. This standardapplies to the power unit only at the power unit location. To testthe sound power level of a central vacuum at the userslocation, refer to Test Method F1334.1.2 A-weighted sound pressure measurements are per-formed on
4、a mounted central vacuum power unit in a semi-reverberant room. This test method determines sound power bya comparison method for small noise sources, that is, compari-son to a broad band reference sound source.1.3 This test method describes a procedure for determiningthe A-weighted sound power leve
5、l of small noise sources. Thistest method uses a non-special semi-reverberant room.1.4 Results are expressed as A-weighted sound power levelin decibels (referenced to 1 pW).1.5 The values stated in inch pound units are to be regardedas the standard. The values in parentheses are for informationonly.
6、1.6 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced D
7、ocuments2.1 ASTM Standards:2C634 Terminology Relating to Building and EnvironmentalAcousticsE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodF820 Test Method for Measuring Air Perf
8、ormance Charac-teristics of Central Vacuum Cleaning SystemsF1334 Test Method for Determining A-Weighted SoundPower Level of Vacuum Cleaners2.2 ANSI Standards:3S1.10 Method for the Calibration of MicrophonesS1.26 Method for the Calculation of the Absorption ofSound by the AtmosphereS1.43 Specificatio
9、ns for Sound Level Meters, IEC 804 andIEC 61672S12.31 Precision Methods for the Determination of SoundPower Levels of Broad Band Noise Sources in Reverber-ant RoomsS12.32 Precision Methods for Determination of SoundPower Levels for Discrete Frequency and Narrow BandNoise Sources in Reverberant Rooms
10、S12.33 Engineering Methods for Determination of SoundPower Levels of Noise Sources in a Special ReverberantTest Room2.3 ISO Standards:3ISO 3741, 3742, and 3743 are similar to and may be used inplace of ANSI S12.31, S12.32, and S12.33 respectively2.4 IEC Standard:360704.1 Test Code for the Determinat
11、ion of AirborneAcoustical Noise Emitted by Household and SimilarElectrical Appliances3. Terminology3.1 Unless otherwise indicated, definitions are in accor-dance with Terminology C634.3.2 Definitions:3.2.1 population, ntotal of all of the units of the particularmodel or type, or both, of central vac
12、uum power units beingtested.3.2.2 population sample or sample, nthree or more units,randomly taken from the population.3.2.3 reference sound source, nstandard source of broad-band sound with a certified set of sound power emissions.3.2.4 source, ndevice that emits sound.1This test method is under th
13、e jurisdiction of ASTM Committee F11 on VacuumCleaners and is the direct responsibility of Subcommittee F11.25 on SoundMeasurement.Current edition approved Nov. 1, 2011. Published December 2011. Originallyapproved in 2006. Last previous edition approved in 2006 as F2544 061. DOI:10.1520/F2544-11.2Fo
14、r referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from American National Standards Institute (ANSI), 25
15、 W. 43rd St.,4th Floor, New York, NY 10036.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.2.5 test unit or units, nsingle central vacuum power unitof the model or type, or both, being tested.4. Significance and Use4.1 The test res
16、ults enable the comparison of A-weightedsound emission from central vacuum power units when testedunder the condition of this test method.5. Test Room Requirements5.1 The test room shall be semi-reverberant. It shall containsufficiently little sound absorption material so the requirementsof 5.2 can
17、be met. It shall be large enough to allow asemi-circle with a 6-ft radius centered at the sound source (thecentral vacuum power unit) that shall be clear of all obstruc-tion, including the operator, during the measurements.5.1.1 The test room should be plumbed for the centralvacuum according to the
18、manufacturers instructions usingstandard 2-in. outside diameter thin-wall PVC tubing. Unitswith multiple exhaust ports shall be plumbed with multipleexhaust lines per manufacturers instructions. Units withoutexhaust ports shall not have an exhaust line plumbed outsidethe test room. The power unit is
19、 to be mounted on the wall perthe manufacturers recommendations.5.2 Three microphone positions are to be used. The micro-phone positions are to be on a semi-circle with a 6-ft radiuscentered at the sound source (the central vacuum power unit).The microphone positions will be spaced 30 from the wall
20、and60 apart from each other on the semi-circle at a height of 60in. (1.5 m). The microphone should be oriented per themicrophone manufacturers instructions. Refer to Fig. 1 forlayout. These positions shall result in a standard deviation ofthe three sound pressure measurements of not more than 2.3 dB
21、when measuring the reference sound source.5.3 EnvironmentalAmbient test conditions within the testroom shall be controlled to 70 6 5F (21 6 3C) and 30 to70 % relative humidity.5.4 Also, any room which has qualified in accordance withANSI S1.26, S12.31, S12.32, S12.33, ISO 3741, 3742, and3743 may be
22、used to measure the sound power levels ofvacuum cleaners.5.5 The measuredA-weighted sound pressure levels shall becorrected for the influence of background noise according toTable 1. When the steady background-noise sound pressurelevel is more than 6 dB below the sound pressure level at eachmeasurem
23、ent point, the measured A-weighted sound pressurelevels shall be corrected for the influence of background noise.If this difference is less than 6 dB, no correction is allowed andany reported data must include a note indicating that thebackground noise requirements of this test method were notsatisf
24、ied.6. Instrumentation and Equipment6.1 Acoustical InstrumentationThe sound measurementsystem shall be as specified in ANSI S1.43.6.2 Voltage Regulator SystemThe regulator shall be ca-pable of maintaining the vacuum cleaners rated voltageFIG. 1 Sound Test LayoutF2544 112(61 %) and frequency (61 Hz)
25、having a waveform that isessentially sinusoidal with 3 % maximum harmonic distortionfor the duration of the test.6.3 Reference Sound SourceThe reference sound sourceshall meet the requirements of Section 9 of ANSI S12.31.6.4 Instrumentation:6.4.1 Thermometer, accurate to 63F (62C).6.4.2 A means of m
26、easuring relative humidity, accurate towithin 62 % over the range used.7. Operation of Central Vacuum Cleaner7.1 Run inOperate new test cleaners continuously for atleast 10 min prior to testing. The central vacuum power unitshould be run with the orifice adapter tube (as specified in TestMethod F820
27、) connected to the power unit inlet (for run-inonly).7.2 Warm upOperate the cleaners for 10 min just prior tomaking sound pressure level measurements in the same con-figuration as shown in Fig. 1.7.3 Test Configuration:7.3.1 The inlet tube and exhaust line should be plumbedwith PVC tubing as far awa
28、y from the test unit as necessary orout of the test room to prevent from contaminating the soundtest. Refer to Fig. 1 for proper test set up of test unit, intaketube, and exhaust line.7.3.2 A muffler should only be attached to the exhaust linebeside the test unit if it is supplied with the test unit
29、. (See Fig.2.)7.3.3 The “end of intake line muffler” is part of the standardtest set-up and should be used on all test units. Its intent is todampen any noise created by the air rushing into the inlet tubeto prevent contamination of the sound measurements of the testunit. This muffler is equipped wi
30、th a34-in. sharp edge orificeplate (taking the place of the hose and floor tool). (See Fig. 2.)7.3.4 The “end of exhaust line muffler” is part of thestandard test set-up and should be used on all test units. Itsintent is to dampen any noise created by the air rushing out ofthe exhaust tube to preven
31、t contamination of the soundmeasurements of the test unit. This muffler does not include anorifice plate. (See Fig. 3.)7.3.5 The dust bag or primary filter shall be new (ifapplicable).7.3.6 VoltageTests are to be conducted at the nameplaterated voltage (61 %) and frequency (61 Hz) throughout thetest
32、. For cleaners with dual nameplate voltage ratings, conductsound tests at the highest voltage.8. Location of Sound Sources and Equipment8.1 Locate the central vacuum power unit at the positiondetermined in 5.1.1.8.2 Locate the reference sound source on the floor (near butnot touching) the wall, belo
33、w the intended location of thevacuum power unit. The microphones should be placed on a6-ft radius from the center of the vacuum power units intendedlocation while testing the reference sound source.9. Measurement Procedure9.1 Check the calibration of each microphone according tothe instrument manufa
34、cturers directions.49.2 At each of the three microphone positions determined in5.2, measure the background A-weighted sound pressure level.Step 9.2 can be ignored if it is known that the backgroundsound pressure levels are more than 10 dB below the soundpressure levels of all sources being considere
35、d at all micro-phone locations.9.3 With the reference sound source in the location definedin Section 8 and running in accordance with the manufacturersrecommendations, measure the A-weighted sound pressurelevel at the microphone positions (as described in 5.2). Aftermaking the necessary corrections
36、for the influence of thebackground noise at each microphone location and ensuringthat the standard deviation requirement of 5.2 is met, calculatethe space-averaged A-weighted sound pressure level of thereference sound source, Lpr, using the equation:Lpor Lpr5 10 logH1Nm(i51Nm10Li/10J(1)where:Lpor Lp
37、r= A-weighted sound pressure level averagedover all microphone positions for a singlesource location, dB,Li= A-weighted sound pressure level for the ithmicrophone position, dB, andNm= number of microphone positions.9.4 Remove the reference sound source and mount the testunit per the manufacturers re
38、commendations. The micro-phones should be positioned as shown in Fig. 1. With the unitoperating in accordance with Section 7, measure theA-weighted sound pressure level at the same microphonelocations. After making the necessary corrections for theinfluence of the background noise at each microphone
39、 location,calculate the space-averaged A-weighted sound pressure level,Lp, of the test unit using the equation in 9.3.9.5 Using the space-averaged A-weighted sound pressurelevels, Lprand Lp, and the known A-weighted sound powerlevel of the reference sound source, calculate the A-weightedsound power
40、level of the test unit using the procedure in 10.1.9.6 Using the same test unit, repeat 9.2-9.5 two additionaltimes for a total of three test runs.9.7 The sound power level (score) for each individual testunit is the arithmetic average of the A-weighted sound powerlevels of three test runs that meet
41、 the repeatability requirements4Further information is provided in ANSI S1.10.TABLE 1 Corrections for Background Noise LevelsDifference between sound pressurelevel measured with sound sourceoperating and background noiselevel alone, dBCorrection to be subtracted from soundpressure level measured wit
42、h soundsource operating to obtain sound pressurelevel due to sound source alone, dBLess than 6 No correction allowed61718190.510 0.5Greater than 10 0F2544 113of Section 14. See Annex A1 for a procedural example and todetermine if additional test runs need to be conducted.9.8 A minimum of two additio
43、nal test units of the samemodel must be selected in accordance with the samplingstatement in Section 11. Repeat 9.2-9.7 for each additional testunit. See Annex A1 for a procedural example and to determineif additional units need to be tested.9.9 The best estimate of A-weighted sound power level fort
44、he population of the central vacuum power unit model beingtested is the arithmetic mean of A-weighted sound power levelof the sample population meeting the requirements of thesampling statement in Section 11.10. Calculation of A-weighted Sound Power Level for theComparison Method10.1 The A-weighted
45、sound power level produced by thetest unit shall be calculated as follows. Subtract theA-weightedsound pressure level produced by the reference sound source(corrected for background noise according to 5.5) from theA-weighted sound pressure level of the test unit under test(corrected for the backgrou
46、nd noise according to 5.5). Add thedifference to the known A-weighted sound power level pro-duced by the reference sound source.LW5 Lwr1 Lp Lpr(2)where:LW= the A-weighted sound power level, in decibels,produced by the test unit under test,Lp= the average A-weighted sound pressure level, indecibels,
47、produced by the test unit under test, asdetermined in accordance with 9.4,Lwr= the known A-weighted sound power level, in deci-bels, produced by the reference sound source, andLpr= the average A-weighted sound pressure level, indecibels, produced by the reference sound source, asdetermined in accord
48、ance with 9.3.11. Sampling11.1 Test a sufficient number of samples of each power unitmodel until a 90 % confidence level is established within 62.0dBA of the mean value. Test a minimum of three samples.12. Information12.1 GeneralRecord the name and location of the testlaboratory, including the date
49、and time of the measurements.12.2 Test RoomRecord the description of the room con-struction, dimensions, configurations, and deployment of ab-sorptive materials, etc.12.3 EquipmentMaintain recorded diagram of the acous-tical data acquisition system. This shall include the modelnumber and serial number of all microphones, preamplifiers,filters, meters, etc. Describe microphone cables specifically.Record the calibrator model number and serial number, outputfrequency, and calibrated level. Record any other pertinentequipment information.12.4 Geometry
