ASTM E1222-90(2002)
(Test Method)Standard Test Method for Laboratory Measurement of the Insertion Loss of Pipe Lagging Systems
Standard Test Method for Laboratory Measurement of the Insertion Loss of Pipe Lagging Systems
SIGNIFICANCE AND USE
The insertion loss of a pipe lagging system depends upon the lagging system materials, the method used to apply the materials, the pipe wall thickness, the size and shape of the bare and lagged pipe, and the mechanisms causing noise radiation from the pipe. Insertion losses measured using this test method should be used with some caution. In the laboratory, measurements must be made under reproducible conditions, but in practical usage in the field, the conditions that determine the effective insertion loss are difficult to predict and they may lead to slightly different results. Insertion losses measured with this test method can be used successfully for acoustical design purposes. Insertion losses measured with this test method are most useful for pipes and lagging systems which are similar to those used in the laboratory configuration.
This test method may be used to rank-order pipe lagging systems according to insertion loss or to estimate the field insertion loss of pipe lagging systems installed in the field.
This test method assumes that pipe wall stresses resulting from different methods of supporting the test pipe in the laboratory do not have a significant effect upon the measured insertion loss.
Pipe lagging systems typically have small insertion loss, and sometimes negative insertion loss, at frequencies below 500 Hz. The results obtained at frequencies below 500 Hz may be somewhat erratic. Sound sources used with this test method normally have a low frequency limit in the range from 300 to 500 Hz. For these reasons, the lowest band of frequencies for which results are required is centered at 500 Hz.
SCOPE
1.1 This test method covers the measurement of the insertion loss of pipe lagging systems under laboratory conditions.
1.2 A procedure for accrediting a laboratory for purposes of this test method is given in Annex A1.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
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Designation:E1222–90(Reapproved 2002)
Standard Test Method for
Laboratory Measurement of the Insertion Loss of Pipe
Lagging Systems
This standard is issued under the fixed designation E1222; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope 4. Summary of Test Method
1.1 This test method covers the measurement of the inser- 4.1 Noise is produced inside a steel pipe located within a
tion loss of pipe lagging systems under laboratory conditions. reverberation room using band-limited white noise as a test
1.2 Aprocedure for accrediting a laboratory for purposes of signal. The noise must be produced by a loudspeaker or
this test method is given in Annex A1. acoustic driver located at one end of the pipe. Average sound
1.3 This standard does not purport to address all of the pressure levels are measured within the reverberation room for
safety concerns, if any, associated with its use. It is the two conditions, one with sound radiating from the bare pipe
responsibility of the user of this standard to establish appro- and the other with the same pipe covered with a lagging
priate safety and health practices and determine the applica- system. The insertion loss of the lagging system is the
bility of regulatory limitations prior to use. difference in the sound pressure levels measured with sound
radiatingfromthebareandlaggedpipe,withanadjustmentfor
2. Referenced Documents
changes in room absorption due to the presence of the lagging
2.1 ASTM Standards:
system.Theresultsmaybeobtainedinaseriesof100-Hzwide
C423 Test Method for Sound Absorption and Sound Ab- bandsorinone-thirdoctavebandsfrom500to5000Hz.Using
sorption Coefficients by the Reverberation Room Method
100-Hzwidebandswillimprovethesignal-to-noiseratiointhe
C634 Terminology Relating to Environmental Acoustics reverberant room. This is frequently necessary when measur-
E90 Test Method for Laboratory Measurement ofAirborne
ing specimens having high insertion loss.
Sound Transmission Loss of Building Partitions and Ele-
5. Significance and Use
ments
2.2 ANSI Standards: 5.1 The insertion loss of a pipe lagging system depends
S1.4 Specification for Sound Level Meters upon the lagging system materials, the method used to apply
S1.6 Preferred Frequencies and Band Numbers for Acous- the materials, the pipe wall thickness, the size and shape of the
tical Measurements bare and lagged pipe, and the mechanisms causing noise
S1.11 SpecificationforOctaveBandandFractional-Octave- radiation from the pipe. Insertion losses measured using this
Band Analog and Digital Filters test method should be used with some caution. In the labora-
tory, measurements must be made under reproducible condi-
3. Terminology
tions, but in practical usage in the field, the conditions that
3.1 Definitions—The acoustical terms used in this test determinetheeffectiveinsertionlossaredifficulttopredictand
method are consistent with Terminology C634.
they may lead to slightly different results. Insertion losses
3.2 Definitions of Terms Specific to This Standard: measured with this test method can be used successfully for
3.2.1 pipe lagging system—an arrangement of noise insu-
acousticaldesignpurposes.Insertionlossesmeasuredwiththis
lating materials used to cover a pipe to reduce noise radiating test method are most useful for pipes and lagging systems
from it.
which are similar to those used in the laboratory configuration.
5.2 Thistestmethodmaybeusedtorank-orderpipelagging
systems according to insertion loss or to estimate the field
This test method is under the jurisdiction of ASTM Committee E33 on
insertion loss of pipe lagging systems installed in the field.
EnvironmentalAcousticsandisthedirectresponsibilityofSubcommitteeE33.08on
Mechanical and Electrical System Noise.
5.3 This test method assumes that pipe wall stresses result-
Current edition approved June 29, 1990. Published August 1990.
ing from different methods of supporting the test pipe in the
Annual Book of ASTM Standards, Vol 04.06.
3 laboratory do not have a significant effect upon the measured
Available from American National Standards Institute, 25 W. 43rd St., 4th
insertion loss.
Floor, New York, NY 10036.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
E1222
5.4 Pipelaggingsystemstypicallyhavesmallinsertionloss, flexible, nonhardening, knife grade mastic, such as available
and sometimes negative insertion loss, at frequencies below forsealinghigh-pressureducts,shouldbeusedtosealthegaps
500Hz.Theresultsobtainedatfrequenciesbelow500Hzmay where the pipe passes through walls.
be somewhat erratic. Sound sources used with this test method 7.3 Loudspeaker:
normally have a low frequency limit in the range from 300 to 7.3.1 Type—The loudspeaker may be a horn-driver combi-
500 Hz. For these reasons, the lowest band of frequencies for nation or a direct radiator (cone type) loudspeaker. Normally,
which results are required is centered at 500 Hz. only acoustic drivers with horns will have sufficient output for
the tests when high insertion losses are being measured.
6. Interferences
7.3.2 Installation—The loudspeaker shall be placed on the
6.1 Flankingtransmissionmaylimitthemaximuminsertion
open end of the pipe outside the reverberation room. The horn
losses which can be reliably measured using this test method.
of the loudspeaker must be structurally isolated from any
The test pipe and reverberation room shall be constructed and
contact with the pipe wall.
arranged so as to minimize the possibility of transmission by
7.4 Reference Sound Source:
paths other than through the test specimen. Flanking transmis-
7.4.1 A reference sound source is needed to permit adjust-
sion should be at least 10 dB lower than the power transmitted
mentsforthechangeinsoundabsorptionwithinthereverbera-
through the test specimen into the reverberation room.Appen- tion room due to the lagging system.
dix X1 presents one procedure for assessing flanking transmis-
7.4.2 The sound from the reference source shall be broad-
sion. band noise without significant single-frequency components.
6.2 The background noise in each test band must be at least
The maximum sound power level of any single frequency
10 dB below measured sound pressure levels for that band. component within a band should be at least 5 dB below the
sound power level for that band.
7. Apparatus
7.4.3 The source level in any band shall have a maximum
7.1 Reverberation Room—The sound field in the reverbera-
short-term time-variation of no greater than 2 dB measured
tion room shall approximate a diffuse field when the test
with the slow dynamic characteristic of a sound level meter or
specimen is in place. The requirements for the reverberation
the equivalent.
room are in Test Method C423. The volume of the test room
7.4.4 Thesourceshallbephysicallysmall,withamaximum
shall be 2000 ft or greater.
dimension of less than 2 ft.
7.1.1 The average sound absorption coefficients of the
7.4.5 The reference source may be a loudspeaker; if so, it
room,excludingsoundabsorptionbyairandthetestspecimen,
shouldbedrivenwithbandsofwhitenoiseanditssoundpower
measured in accordance with Test Method C423, shall be less
output should be within the limits prescribed in 7.4.3.
than0.06overthetestfrequencyrangewhenthetestspecimen
7.4.6 A preferred reference sound source is a modified
is in place.
centrifugalfan,directlyconnectedtoamotorwithstablespeed
7.1.2 Diffusing devices such as rotating and stationary
characteristics. The sound power level of this source as a
diffusing surfaces are useful for creating an adequate diffuse
function of frequency is adequately constant for this test
sound field.
method.
7.2 Pipe:
7.4.7 The source should have a resilient mounting which is
7.2.1 Construction—The standard test pipe shall be at least
suitably designed to prevent transmission of vibrations to the
13 ft long and mounted horizontally within the reverberation
structure on which it is mounted.
room. It shall be a nominal 12-in. diameter carbon steel pipe
8. Test Specimen
with a nominal wall thickness of ⁄4 in.
7.2.2 Other pipes may be used but they shall have a wall
8.1 The test specimen shall be a pipe lagging system
thickness of at least ⁄4 in., a nominal diameter of at least 6 in.,
installed on the bare pipe following normal mounting proce-
and shall be at least 13 diameters long.
dure. The system should be lapped and seamed following a
7.2.3 Installation—Potential flanking transmission can be
procedure similar to the one used in the field.
minimized if both ends of the pipe are outside of the rever-
8.2 If the pipe lagging system is usually installed with a
beration room. For this reason, this is the preferred method of
seam,thetestspecimenshallhaveatleastoneseamaroundthe
installing the pipe.Alternately, the loudspeaker end of the pipe
circumference and one longitudinal seam.
may be located outside of the reverberation room. In this case,
8.3 The test specimen should be sealed where it butts to the
theotherendofthepipewithinthereverberationroommustbe
walls of the reverberation room or the capped end of the pipe.
carefully constructed and mounted to avoid flanking transmis-
The flexible mastic used to seal gaps around the pipe is also
sion. Any method of terminating the pipe may be used
recommended for this purpose. The mastic should not harden
provided that adequately low levels of flanking transmission
with age so as to cause flanking.
are achieved. It is usually necessary to cap the end of the pipe
within the reverberation room with heavy structure and to
vibration-isolatethepipeendfromthereverberationroomfloor
Soundsourcesthathavebeenfoundsuitableforthispurposeareavailablefrom
Brüel and Kjäer Instruments, Inc., 185 Forest St., Marlborough, MA01752 (Model
orceiling.Thecapmaybeablindflange,atleasttwiceasthick
4204); ILG Industries, 2850 North Pulaski Road, Chicago, IL60641; Electric
as the pipe wall, welded to the end of the pipe.
France (E.D.F.), Department Acoustique et Vibrations, 17, Av. de la Liberation, 92
7.2.4 No solid connections may exist between the surfaces
Clamart, France (Model NOVACEM); and, Acculab, 3201 Ridgewood Drive,
of the reverberation room and the pipe or test specimen. A Columbus, OH43220.
E1222
9. Test Signal each test band within the reverberation room. Measure the
sound pressure levels generated by the test signal at the
9.1 The loudspeaker shall be driven with bands of white
monitoring microphone inside the pipe.
noise. To avoid nonlinearities, the total sound pressure level
11.5 Remove the test specimen from the pipe while main-
shall not exceed 160 dB inside the pipe.
taining the entire equipment set-up including all source and
9.2 The sound pressure level in the test band on the interior
measuring instrument settings as far as practical. A precision
of the pipe shall have a maximum short-term time-variation in
stepattenuatormaybeusedtotemporarilylowerthetestsignal
any band no greater than 2 dB measured with the “slow”
drivingtheloudspeakerwhileremovingthetestspecimen.Itis
dynamiccharacteristicofasoundlevelmeterortheequivalent.
of the utmost importance to make no changes in the loud-
If necessary, longer time averages may be used.
speaker position.
9.3 Test Frequency Bands:
11.6 Return the test signal to the previous setting.
9.3.1 Constant Bandwidth Method—The test signal shall be
11.7 Compare the sound pressure levels generated by the
contiguous 100 Hz (610 Hz), wide bands of white noise with
test signal at the monitoring microphone with the spectrum
arithmetic center frequencies over the nominal range from 500
measured in 11.4. If the test signal, with sufficient time
to5,000Hz.Optionally,bandscenteredat300and400Hzmay
averaging,differsbymorethan2dBinanytestbandfromthat
also be used.
measured in 11.4 with the test specimen in place, begin the
9.3.2 One-third Octave-band Method—The test signal shall
procedure again.
be contiguous one-third octave bands of white noise at the
preferredone-thirdoctavebandcenterfrequenciesfrom500to 11.8 Measure the average sound pressure levels in each test
band within the reverberation room. Turn the test signal off.
5000 Hz. Optionally, one-third octave bands from 315 to 5000
Hz may be used.
11.9 Repeat step 11.3 for the bare pipe.
11.10 If another specimen is to be tested, repeat all steps
10. Measuring Instruments
outlined in 11.1-11.9.
10.1 The minimum instrumentation required for this test
method is as follows:
12. Calculation
10.1.1 A monitoring microphone located inside the test
12.1 Ineachtestfrequencyband,calculatetheinsertionloss
pipe,
of the test specimen as follows:
10.1.2 One or more room measurement microphones lo-
IL 5 Lb 2 Ll 2 @Lbr 2 Llr# (1)
cated in the reverberation room,
10.1.3 Microphone amplifiers that satisfy the requirements
ofANSI S1.4 for Type 1 or better sound level meters with the
where:
exception that A and B-weighting networks are not required,
IL = insertion loss, dB,
and
Lb,Ll = average sound pressure level measured with
10.1.4 Alevel meter, graphic level recorder, or other device
sound radiating from the bare pipe and lagged
from which the sound pressure level can be read or recorded.
pipe respectively, dB, and
The averaging time of the instruments shall be sufficient to
Lbr,Llr = average sound pressure level measured with the
permit the determination of the average sound pressure level
reference sound source with the bare and lagged
with adequate precision.
pipe, respectively, dB.
10.2 Measuring filters are required and depend upon the
method selected:
13. Report
10.2.1 Constant Bandwidth Method—Nominal 100-Hz
13.1 Report the following information:
wideconstantbandwidthfilterswitharithmeticcenterfrequen-
13.1.1 A statement, if true in every respect, that the tests
cies consistent with the test signal frequency range.
were conducted in accordance with the provisions of this test
10.2.2 One-third Octave-Band Method—Aone-third octave
method. Conformance to the relevant sections ofAppendix X1
filter set satisfying the requirements of ANSI S1.11 for Order
shall also be reported when applicable. Report any exceptions
3orhigher,Type1orbetter.Thenominalcenterfrequenciesof
to this test method, including nonstandard pipes.
the filters shall be the same as the test signal center frequency.
13.1.2 A description of the test specimen. The description
10.3 A narrow band analyzer is optional. It may be useful
shouldbesufficientlydetailedtoidentifytheelementsthatmay
formon
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