ASTM E1222-90(1996)e1
(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
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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e1
Designation: E 1222 – 90 (Reapproved 1996)
Standard Test Method for
Laboratory Measurement of the Insertion Loss of Pipe
Lagging Systems
This standard is issued under the fixed designation E 1222; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
e NOTE—Keywords were added editorially in June 1996.
1. Scope reverberation room using band-limited white noise as a test
signal. The noise must be produced by a loudspeaker or
1.1 This test method covers the measurement of the inser-
acoustic driver located at one end of the pipe. Average sound
tion loss of pipe lagging systems under laboratory conditions.
pressure levels are measured within the reverberation room for
1.2 A procedure for accrediting a laboratory for purposes of
two conditions, one with sound radiating from the bare pipe
this test method is given in Annex A1.
and the other with the same pipe covered with a lagging
1.3 This standard does not purport to address all of the
system. The insertion loss of the lagging system is the
safety concerns, if any, associated with its use. It is the
difference in the sound pressure levels measured with sound
responsibility of the user of this standard to establish appro-
radiating from the bare and lagged pipe, with an adjustment for
priate safety and health practices and determine the applica-
changes in room absorption due to the presence of the lagging
bility of regulatory limitations prior to use.
system. The results may be obtained in a series of 100-Hz wide
2. Referenced Documents bands or in one-third octave bands from 500 to 5000 Hz. Using
100-Hz wide bands will improve the signal-to-noise ratio in the
2.1 ASTM Standards:
reverberant room. This is frequently necessary when measur-
C 423 Test Method for Sound Absorption and Sound Ab-
ing specimens having high insertion loss.
sorption Coefficients by the Reverberation Room Method
C 634 Terminology Relating to Environmental Acoustics
5. Significance and Use
E 90 Test Method for Laboratory Measurement of Airborne
5.1 The insertion loss of a pipe lagging system depends
Sound Transmission Loss of Building Partitions
upon the lagging system materials, the method used to apply
2.2 ANSI Standards:
the materials, the pipe wall thickness, the size and shape of the
S1.4 Specification for Sound Level Meters
bare and lagged pipe, and the mechanisms causing noise
S1.6 Preferred Frequencies and Band Numbers for Acous-
radiation from the pipe. Insertion losses measured using this
tical Measurements
test method should be used with some caution. In the labora-
S1.11 Specification for Octave Band and Fractional-Octave-
tory, measurements must be made under reproducible condi-
Band Analog and Digital Filters
tions, but in practical usage in the field, the conditions that
3. Terminology determine the effective insertion loss are difficult to predict and
they may lead to slightly different results. Insertion losses
3.1 Definitions—The acoustical terms used in this test
measured with this test method can be used successfully for
method are consistent with Terminology C 634.
acoustical design purposes. Insertion losses measured with this
3.2 Definitions of Terms Specific to This Standard:
test method are most useful for pipes and lagging systems
3.2.1 pipe lagging system—an arrangement of noise insu-
which are similar to those used in the laboratory configuration.
lating materials used to cover a pipe to reduce noise radiating
5.2 This test method may be used to rank-order pipe lagging
from it.
systems according to insertion loss or to estimate the field
4. Summary of Test Method
insertion loss of pipe lagging systems installed in the field.
5.3 This test method assumes that pipe wall stresses result-
4.1 Noise is produced inside a steel pipe located within a
ing from different methods of supporting the test pipe in the
laboratory do not have a significant effect upon the measured
This test method is under the jurisdiction of ASTM Committee E-33 on
insertion loss.
Environmental Acoustics and is the direct responsibility of Subcommittee E33.08 on
Mechanical and Electrical System Noise. 5.4 Pipe lagging systems typically have small insertion loss,
Current edition approved June 29, 1990. Published August 1990.
and sometimes negative insertion loss, at frequencies below
Annual Book of ASTM Standards, Vol 04.06.
500 Hz. The results obtained at frequencies below 500 Hz may
Available from American National Standards Institute, 11 W. 42nd St., 13th
be somewhat erratic. Sound sources used with this test method
Floor, New York, NY 10036.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
E 1222
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 Flanking transmission may limit the maximum insertion
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
ments for the change in sound absorption within the reverbera-
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 C 423. The volume of the test room
7.4.4 The source shall be physically small, with a maximum
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, excluding sound absorption by air and the test specimen,
should be driven with bands of white noise and its sound power
measured in accordance with Test Method C 423, shall be less
output should be within the limits prescribed in 7.4.3.
than 0.06 over the test frequency range when the test specimen
7.4.6 A preferred reference sound source is a modified
is in place.
centrifugal fan, directly connected to a motor with stable speed
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.
8.1 The test specimen shall be a pipe lagging system
7.2.2 Other pipes may be used but they shall have a wall
thickness of at least ⁄4 in., a nominal diameter of at least 6 in., installed on the bare pipe following normal mounting proce-
dure. The system should be lapped and seamed following a
and shall be at least 13 diameters long.
7.2.3 Installation—Potential flanking transmission can be procedure similar to the one used in the field.
8.2 If the pipe lagging system is usually installed with a
minimized if both ends of the pipe are outside of the rever-
beration room. For this reason, this is the preferred method of seam, the test specimen shall have at least one seam around the
circumference and one longitudinal seam.
installing the pipe. Alternately, the loudspeaker end of the pipe
may be located outside of the reverberation room. In this case, 8.3 The test specimen should be sealed where it butts to the
walls of the reverberation room or the capped end of the pipe.
the other end of the pipe within the reverberation room must be
The flexible mastic used to seal gaps around the pipe is also
carefully constructed and mounted to avoid flanking transmis-
recommended for this purpose. The mastic should not harden
sion. Any method of terminating the pipe may be used
with age so as to cause flanking.
provided that adequately low levels of flanking transmission
are achieved. It is usually necessary to cap the end of the pipe
9. Test Signal
within the reverberation room with heavy structure and to
9.1 The loudspeaker shall be driven with bands of white
vibration-isolate the pipe end from the reverberation room floor
noise. To avoid nonlinearities, the total sound pressure level
or ceiling. The cap may be a blind flange, at least twice as thick
shall not exceed 160 dB inside the pipe.
as the pipe wall, welded to the end of the pipe.
7.2.4 No solid connections may exist between the surfaces
of the reverberation room and the pipe or test specimen. A
Sound sources that have been found suitable for this purpose are available from
Brüel and Kjäer Instruments, Inc., 185 Forest St., Marlborough, MA 01752 (Model
flexible, nonhardening, knife grade mastic, such as available
4204); ILG Industries, 2850 North Pulaski Road, Chicago, IL 60641; Electric
for sealing high-pressure ducts, should be used to seal the gaps
France (E.D.F.), Department Acoustique et Vibrations, 17, Av. de la Liberation, 92
where the pipe passes through walls.
Clamart, France (Model NOVACEM); and, Acculab, 3201 Ridgewood Drive,
7.3 Loudspeaker: Columbus, OH 43220.
E 1222
9.2 The sound pressure level in the test band on the interior taining the entire equipment set-up including all source and
of the pipe shall have a maximum short-term time-variation in measuring instrument settings as far as practical. A precision
any band no greater than 2 dB measured with the “slow” step attenuator may be used to temporarily lower the test signal
dynamic characteristic of a sound level meter or the equivalent. driving the loudspeaker while removing the test specimen. It is
If necessary, longer time averages may be used. of the utmost importance to make no changes in the loud-
9.3 Test Frequency Bands: speaker position.
9.3.1 Constant Bandwidth Method—The test signal shall be 11.6 Return the test signal to the previous setting.
contiguous 100 Hz (610 Hz), wide bands of white noise with 11.7 Compare the sound pressure levels generated by the
arithmetic center frequencies over the nominal range from 500 test signal at the monitoring microphone with the spectrum
to 5,000 Hz. Optionally, bands centered at 300 and 400 Hz may measured in 11.4. If the test signal, with sufficient time
also be used. averaging, differs by more than 2 dB in any test band from that
9.3.2 One-third Octave-band Method—The test signal shall measured in 11.4 with the test specimen in place, begin the
be contiguous one-third octave bands of white noise at the procedure again.
preferred one-third octave band center frequencies from 500 to 11.8 Measure the average sound pressure levels in each test
5000 Hz. Optionally, one-third octave bands from 315 to 5000 band within the reverberation room. Turn the test signal off.
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
12. Calculation
method is as follows:
10.1.1 A monitoring microphone located inside the test
12.1 In each test frequency band, calculate the insertion loss
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
where:
IL 5 insertion loss, dB,
of ANSI S1.4 for Type 1 or better sound level meters with the
Lb,Ll 5 average sound pressure level measured with
exception that A and B-weighting networks are not required,
and sound radiating from the bare pipe and lagged
pipe respectively, dB, and
10.1.4 A level meter, graphic level recorder, or other device
Lbr,Llr 5 average sound pressure level measured with the
from which the sound pressure level can be read or recorded.
reference sound source with the bare and lagged
The averaging time of the instruments shall be sufficient to
pipe, respectively, dB.
permit the determination of the average sound pressure level
with adequate precision.
13. Report
10.2 Measuring filters are required and depend upon the
13.1 Report the following information:
method selected:
13.1.1 A statement, if true in every respect, that the tests
10.2.1 Constant Bandwidth Method—Nominal 100-Hz
were conducted in accordance with the provisions of this test
wide constant bandwidth filters with arithmetic center frequen-
method. Conformance to the relevant sections of Appendix X1
cies consistent with the test signal frequency range.
shall also be reported when applicable. Report any exceptions
10.2.2 One-third Octave-Band Method—A one-third octave
to this test method, including nonstandard pipes.
filter set satisfying the requirements of ANSI S1.11 for Order
13.1.2 A description of the test specimen. The description
3 or higher, Type 1 or better. The nominal center frequencies of
should be sufficiently detailed to ide
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