1、Designation: E1222 90 (Reapproved 2016)Standard Test Method forLaboratory Measurement of the Insertion Loss of PipeLagging Systems1This standard is issued under the fixed designation E1222; the number immediately following the designation indicates the year oforiginal adoption or, in the case of rev
2、ision, 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 covers the measurement of the inser-tion loss of pipe lagging systems under labora
3、tory conditions.1.2 A procedure for accrediting a laboratory for purposes ofthis test method is given in Annex A1.1.3 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 s
4、afety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2C423 Test Method for SoundAbsorption and SoundAbsorp-tion Coefficients by the Reverberation Room MethodC634 Terminology Relating to Building and Environmental
5、AcousticsE90 Test Method for Laboratory Measurement of AirborneSound Transmission Loss of Building Partitions andElementsE548 Guide for General Criteria Used for Evaluating Labo-ratory Competence (Withdrawn 2002)32.2 ANSI Standards:S1.4 Specification for Sound Level Meters4S1.6 Preferred Frequencies
6、 and Band Numbers for Acousti-cal Measurements4S1.11 Specification for Octave Band and Fractional-Octave-Band Analog and Digital Filters43. Terminology3.1 DefinitionsThe acoustical terms used in this testmethod are consistent with Terminology C634.3.2 Definitions of Terms Specific to This Standard:3
7、.2.1 pipe lagging systeman arrangement of noise insulat-ing materials used to cover a pipe to reduce noise radiatingfrom it.4. Summary of Test Method4.1 Noise is produced inside a steel pipe located within areverberation room using band-limited white noise as a testsignal. The noise must be produced
8、 by a loudspeaker oracoustic driver located at one end of the pipe. Average soundpressure levels are measured within the reverberation room fortwo conditions, one with sound radiating from the bare pipeand the other with the same pipe covered with a laggingsystem. The insertion loss of the lagging s
9、ystem is thedifference in the sound pressure levels measured with soundradiating from the bare and lagged pipe, with an adjustment forchanges in room absorption due to the presence of the laggingsystem. The results may be obtained in a series of 100-Hz widebands or in one-third octave bands from 500
10、 to 5000 Hz. Using100-Hz wide bands will improve the signal-to-noise ratio in thereverberant room. This is frequently necessary when measur-ing specimens having high insertion loss.5. Significance and Use5.1 The insertion loss of a pipe lagging system dependsupon the lagging system materials, the me
11、thod used to applythe materials, the pipe wall thickness, the size and shape of thebare and lagged pipe, and the mechanisms causing noiseradiation from the pipe. Insertion losses measured using thistest method should be used with some caution. In thelaboratory, measurements must be made under reprod
12、ucibleconditions, but in practical usage in the field, the conditionsthat determine the effective insertion loss are difficult to predictand they may lead to slightly different results. Insertion lossesmeasured with this test method can be used successfully foracoustical design purposes. Insertion l
13、osses measured with thistest method are most useful for pipes and lagging systemswhich are similar to those used in the laboratory configuration.1This test method is under the jurisdiction ofASTM Committee E33 on Buildingand Environmental Acoustics and is the direct responsibility of SubcommitteeE33
14、.08 on Mechanical and Electrical System Noise.Current edition approved Oct. 1, 2016. Published October 2016. Originallyapproved in 1990. Last previous edition approved in 2009 as E1222 90 (2009).DOI: 10.1520/E1222-90R16.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact
15、ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.4Available from American National Standards Institute (AN
16、SI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.orgCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States15.2 This test method may be used to rank-order pipe laggingsystems according to insertion loss or to estimate the fie
17、ldinsertion loss of pipe lagging systems installed in the field.5.3 This test method assumes that pipe wall stresses result-ing from different methods of supporting the test pipe in thelaboratory do not have a significant effect upon the measuredinsertion loss.5.4 Pipe lagging systems typically have
18、 small insertion loss,and sometimes negative insertion loss, at frequencies below500 Hz. The results obtained at frequencies below 500 Hz maybe somewhat erratic. Sound sources used with this test methodnormally have a low frequency limit in the range from 300 to500 Hz. For these reasons, the lowest
19、band of frequencies forwhich results are required is centered at 500 Hz.6. Interferences6.1 Flanking transmission may limit the maximum insertionlosses which can be reliably measured using this test method.The test pipe and reverberation room shall be constructed andarranged so as to minimize the po
20、ssibility of transmission bypaths other than through the test specimen. Flanking transmis-sion should be at least 10 dB lower than the power transmittedthrough the test specimen into the reverberation room. Appen-dix X1 presents one procedure for assessing flanking transmis-sion.6.2 The background n
21、oise in each test band must be at least10 dB below measured sound pressure levels for that band.7. Apparatus7.1 Reverberation RoomThe sound field in the reverbera-tion room shall approximate a diffuse field when the testspecimen is in place. The requirements for the reverberationroom are in Test Met
22、hod C423. The volume of the test roomshall be 2000 ft3or greater.7.1.1 The average sound absorption coefficients of theroom, excluding sound absorption by air and the test specimen,measured in accordance with Test Method C423, shall be lessthan 0.06 over the test frequency range when the test specim
23、enis in place.7.1.2 Diffusing devices such as rotating and stationarydiffusing surfaces are useful for creating an adequate diffusesound field.7.2 Pipe:7.2.1 ConstructionThe standard test pipe shall be at least13 ft long and mounted horizontally within the reverberationroom. It shall be a nominal 12
24、-in. diameter carbon steel pipewith a nominal wall thickness of14 in.7.2.2 Other pipes may be used but they shall have a wallthickness of at least14 in., a nominal diameter of at least 6 in.,and shall be at least 13 diameters long.7.2.3 InstallationPotential flanking transmission can beminimized if
25、both ends of the pipe are outside of the rever-beration room. For this reason, this is the preferred method ofinstalling the pipe. Alternately, the loudspeaker end of the pipemay be located outside of the reverberation room. In this case,the other end of the pipe within the reverberation room must b
26、ecarefully constructed and mounted to avoid flanking transmis-sion. Any method of terminating the pipe may be usedprovided that adequately low levels of flanking transmissionare achieved. It is usually necessary to cap the end of the pipewithin the reverberation room with heavy structure and tovibra
27、tion-isolate the pipe end from the reverberation room flooror ceiling. The cap may be a blind flange, at least twice as thickas the pipe wall, welded to the end of the pipe.7.2.4 No solid connections may exist between the surfacesof the reverberation room and the pipe or test specimen. Aflexible, no
28、nhardening, knife grade mastic, such as availablefor sealing high-pressure ducts, should be used to seal the gapswhere the pipe passes through walls.7.3 Loudspeaker:7.3.1 TypeThe loudspeaker may be a horn-driver combi-nation or a direct radiator (cone type) loudspeaker. Normally,only acoustic driver
29、s with horns will have sufficient output forthe tests when high insertion losses are being measured.7.3.2 InstallationThe loudspeaker shall be placed on theopen end of the pipe outside the reverberation room. The hornof the loudspeaker must be structurally isolated from anycontact with the pipe wall
30、.7.4 Reference Sound Source:7.4.1 A reference sound source is needed to permit adjust-ments for the change in sound absorption within the reverbera-tion room due to the lagging system.7.4.2 The sound from the reference source shall be broad-band noise without significant single-frequency components.
31、The maximum sound power level of any single frequencycomponent within a band should be at least 5 dB below thesound power level for that band.7.4.3 The source level in any band shall have a maximumshort-term time-variation of no greater than 2 dB measuredwith the slow dynamic characteristic of a sou
32、nd level meter orthe equivalent.7.4.4 The source shall be physically small, with a maximumdimension of less than 2 ft.7.4.5 The reference source may be a loudspeaker; if so, itshould be driven with bands of white noise and its sound poweroutput should be within the limits prescribed in 7.4.3.7.4.6 A
33、 preferred reference sound source is a modifiedcentrifugal fan, directly connected to a motor with stable speedcharacteristics. The sound power level of this source as afunction of frequency is adequately constant for this testmethod.57.4.7 The source should have a resilient mounting which issuitabl
34、y designed to prevent transmission of vibrations to thestructure on which it is mounted.5The sole sources of supply of the sound sources known to the committee at thistime are Brel and Kjer Instruments, Inc., 185 Forest St., Marlborough, MA 01752(Model 4204); ILG Industries, 2850 North Pulaski Road,
35、 Chicago, IL 60641;Electric France (E.D.F.), Department Acoustique et Vibrations, 17, Av. de laLiberation, 92 Clamart, France (Model NOVACEM); and, Acculab, 3201 Ridge-wood Drive, Columbus, OH 43220 If you are aware of alternative suppliers, pleaseprovide this information to ASTM International Headq
36、uarters. Your comments willreceive careful consideration at a meeting of the responsible technical committee,1which you may attend.E1222 90 (2016)28. Test Specimen8.1 The test specimen shall be a pipe lagging systeminstalled on the bare pipe following normal mounting proce-dure. The system should be
37、 lapped and seamed following aprocedure similar to the one used in the field.8.2 If the pipe lagging system is usually installed with aseam, the test specimen shall have at least one seam around thecircumference and one longitudinal seam.8.3 The test specimen should be sealed where it butts to thewa
38、lls of the reverberation room or the capped end of the pipe.The flexible mastic used to seal gaps around the pipe is alsorecommended for this purpose. The mastic should not hardenwith age so as to cause flanking.9. Test Signal9.1 The loudspeaker shall be driven with bands of whitenoise. To avoid non
39、linearities, the total sound pressure levelshall not exceed 160 dB inside the pipe.9.2 The sound pressure level in the test band on the interiorof the pipe shall have a maximum short-term time-variation inany band no greater than 2 dB measured with the “slow”dynamic characteristic of a sound level m
40、eter or the equivalent.If necessary, longer time averages may be used.9.3 Test Frequency Bands:9.3.1 Constant Bandwidth MethodThe test signal shall becontiguous 100 Hz (610 Hz), wide bands of white noise witharithmetic center frequencies over the nominal range from 500to 5,000 Hz. Optionally, bands
41、centered at 300 and 400 Hz mayalso be used.9.3.2 One-third Octave-band MethodThe test signal shallbe contiguous one-third octave bands of white noise at thepreferred one-third octave band center frequencies from 500 to5000 Hz. Optionally, one-third octave bands from 315 to 5000Hz may be used.10. Mea
42、suring Instruments10.1 The minimum instrumentation required for this testmethod is as follows:10.1.1 A monitoring microphone located inside the testpipe,10.1.2 One or more room measurement microphones lo-cated in the reverberation room,10.1.3 Microphone amplifiers that satisfy the requirementsof ANS
43、I S1.4 for Type 1 or better sound level meters with theexception that A and B-weighting networks are not required,and10.1.4 A level meter, graphic level recorder, or other devicefrom which the sound pressure level can be read or recorded.The averaging time of the instruments shall be sufficient tope
44、rmit the determination of the average sound pressure levelwith adequate precision.10.2 Measuring filters are required and depend upon themethod selected:10.2.1 Constant Bandwidth MethodNominal 100-Hz wideconstant bandwidth filters with arithmetic center frequenciesconsistent with the test signal fre
45、quency range.10.2.2 One-third Octave-Band MethodA one-third octavefilter set satisfying the requirements of ANSI S1.11 for Order3 or higher, Type 1 or better. The nominal center frequencies ofthe filters shall be the same as the test signal center frequency.10.3 A narrow band analyzer is optional. I
46、t may be usefulfor monitoring spectral uniformity of the sound within the pipe.11. Procedure11.1 Install the lagging specimen on the pipe.11.2 Select microphone positions within the reverberationroom. The locations shall be at least one-half wavelength awayfrom any solid surface at the lowest test f
47、requency.11.3 Using the reference sound source, measure the averagesound pressure levels in each test band within the reverberationroom. Turn off the reference sound source.11.4 Drive the loudspeaker at the end of the pipe with thetest signal and measure the average sound pressure levels ineach test
48、 band within the reverberation room. Measure thesound pressure levels generated by the test signal at themonitoring microphone inside the pipe.11.5 Remove the test specimen from the pipe while main-taining the entire equipment set-up including all source andmeasuring instrument settings as far as pr
49、actical. A precisionstep attenuator may be used to temporarily lower the test signaldriving the loudspeaker while removing the test specimen. It isof the utmost importance to make no changes in the loud-speaker position.11.6 Return the test signal to the previous setting.11.7 Compare the sound pressure levels generated by thetest signal at the monitoring microphone with the spectrummeasured in 11.4. If the test signal, with sufficient timeaveraging, differs by more than 2 dB in any test band from thatmeasured in 11.4 with the test specimen in place, begin theprocedur
