ASTM E795-05(2012)
(Practice)Standard Practices for Mounting Test Specimens During Sound Absorption Tests
Standard Practices for Mounting Test Specimens During Sound Absorption Tests
SIGNIFICANCE AND USE
4.1 The sound absorption of a material that covers a flat surface depends not only on the physical properties of the material but also on the way in which the material is mounted over the surface. The mountings specified in these practices are intended to simulate in the laboratory conditions that exist in normal use.
4.2 Some of the specified mountings require special fixtures or minor deviations from normal practice. These fixtures or deviations are to be used only during laboratory tests and should not be specified for practical installations. They are noted in the specifications for the mountings in question by the phrase “for laboratory testing only.”
4.3 Test reports may refer to these mountings by type designation instead of providing a detailed description of the mounting used.
SCOPE
1.1 These practices cover test specimen mountings to be used during sound absorption tests performed in accordance with Test Method C423.
1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
General Information
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: E795 − 05(Reapproved 2012)
Standard Practices for
Mounting Test Specimens During Sound Absorption Tests
This standard is issued under the fixed designation E795; 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 (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope 3.2.2 test surface—any hard surface over which the test
specimen or test specimen mounting is placed for testing in
1.1 These practices cover test specimen mountings to be
accordance with Test Method C423. The surface shall satisfy
used during sound absorption tests performed in accordance
the room construction requirements of Test Method C423.In
with Test Method C423.
most cases, the surface will be the floor of the reverberation
1.2 The values stated in SI units are to be regarded as the
room.
standard. The values given in parentheses are for information
only.
4. Significance and Use
4.1 The sound absorption of a material that covers a flat
2. Referenced Documents
surface depends not only on the physical properties of the
2.1 ASTM Standards:
material but also on the way in which the material is mounted
C423 Test Method for SoundAbsorption and SoundAbsorp-
over the surface.The mountings specified in these practices are
tion Coefficients by the Reverberation Room Method
intended to simulate in the laboratory conditions that exist in
C634 Terminology Relating to Building and Environmental
normal use.
Acoustics
4.2 Some of the specified mountings require special fixtures
2.2 ISO Standard:
or minor deviations from normal practice. These fixtures or
ISO 354 Measurement of SoundAbsorption in a Reverbera-
deviations are to be used only during laboratory tests and
tion Room
should not be specified for practical installations. They are
noted in the specifications for the mountings in question by the
3. Terminology
phrase “for laboratory testing only.”
3.1 Definitions of Terms Specific to This Standard:
3.1.1 Except as noted in 4.2, the terms used in these
4.3 Test reports may refer to these mountings by type
practices are defined in Terminology C634.
designation instead of providing a detailed description of the
3.2 The following terms have the meaning noted for these
mounting used.
practices only:
3.2.1 sound-absorbing units — consists of test specimens
5. Classification
that are in direct contact with or suspended from ceilings,
5.1 The mountings are designated as follows:
walls, or other room surfaces. Sound-absorbing units include,
5.1.1 Type A Mounting—Test specimen laid directly against
but are not limited to, baffles, draperies, space absorbers,
the test surface (described in detail in Section 6).
volume absorbers (bass traps), and other three-dimensional
objects. 5.1.2 Type B Mounting—Test specimen cemented to gyp-
sum board and laid directly against the test surface (described
in detail in Section 7).
These practices are under the jurisdiction of ASTM Committee E33 on
5.1.3 Type C Mounting—Test specimen comprising sound-
Building and EnvironmentalAcoustics and are the direct responsibility of Subcom-
absorptive material behind a perforated, expanded, open facing
mittee E33.01 on Sound Absorption.
or other porous material (described in detail in Section 8).
Current edition approved Sept. 1, 2012. Published November 2012. Originally
approved in 1981. Last previous edition approved in 2005 as E795 – 05. DOI:
5.1.4 Type D Mounting—Test specimen mounted on wood
10.1520/E0795-05R12.
furring strips (described in detail in Section 9).
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM 5.1.5 Type E Mounting—Test specimen mounted with an air
Standards volume information, refer to the standard’s Document Summary page on
space behind it (described in detail in Section 10).
the ASTM website.
5.1.6 Type F Mounting—Test specimen mounted with an air
Available from American National Standards Institute (ANSI), 25 W. 43rd St.,
4th Floor, New York, NY 10036. space behind it (described in detail in Section 11).
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E795 − 05 (2012)
5.1.7 Type G Mounting—Test specimen is a drapery, win- joints are sealed in this manner, the test report shall describe
dow shade, or blind hung parallel to the test surface (described the method of sealing.
in detail in Section 12).
6.4 Perimeter Seals for Laboratory Testing Only—If the
5.1.8 Type H Mounting—Test specimen is a drapery sus-
perimeter edges of the test specimen are not exposed in normal
pended away from any vertical surface (described in detail in
use, seal them by one of the following two methods:
Section 13).
6.4.1 Cover with tape, caulking compound, or a similar
5.1.9 Type I Mounting—The specimen is a spray- or trowel-
product as shown in Fig. 2.
applied material on an acoustically hard substrate (described in
6.4.2 Cover with a wood or metal frame so that the top
detail in Section 14).
surface of the frame is flush with the front face of the test
5.1.10 Type J Mounting—The specimen is a sound-
specimen as shown in Fig. 2. Minimize air spaces between the
absorbing unit or set of sound-absorbing units (described in
frame and the perimeter edge of the test specimen. Air gaps
detail in Section 15).
between the bottom of the frame and the test surface shall be
5.1.11 Type K Mounting—Test specimen is an office screen
sealed with duct tape or caulking.
(described in detail in Section 16).
NOTE 1—The Type A mounting is intended to simulate normal use
5.1.12 Type L Mounting—This mounting is for use with
where a product, such as carpet, wall panels, or ceiling tile is either laid
concrete blocks or block-like specimens that are normally
directly on the floor or attached to a wall or ceiling with adhesive or
assembled using mortar (described in detail in Section 17).
mechanical fasteners. Panels or tiles arranged as independent units, that is,
5.1.13 Type M Mounting—Test specimen is theater seats, (
not butted together at the edges to form a single extended plane, are to be
tested as a Type J mounting.
described in detail in Section 18).
5.2 Type C, D, E, and G mountings are further designated
7. Type B Mounting
by a numerical suffix which indicates the distance (in millime-
7.1 Adhere the test specimen to gypsum board laid directly
tres) from the specimen to the test surface rounded to the
against the test surface as shown in Fig. 3.The thickness of the
nearest integral multiple of 5 mm. For example, a Type E-400
gypsum board is not critical.
mounting is a plenum mounting in which the face of the test
specimen is 400 mm (15 ⁄4 in.) away from the test surface. The
7.2 Apply the adhesive in accordance with the manufactur-
distances specified by the suffixes are as follows:
er’sinstructions.Iftherearenospecificinstructions,applyfour
5.2.1 For a Type C Mounting—The thickness of the furring
daubs of adhesive to the back of each piece of the test
strips.
specimen.
5.2.2 For a Type D Mounting—The thickness of the furring
7.3 For Laboratory Testing Only—Place 3 by 25 by 25-mm
strips.
( ⁄8 by 1 by 1-in.) hardboard shims between the test specimen
5.2.3 For a Type E Mounting—The distance from the
and the gypsum board at the four corners of each piece of test
exposed face of the test specimen to the test surface.
specimen.
5.2.4 For a Type F Mounting—The thickness of the spacers.
5.2.5 For a Type G Mounting—The distance from the 7.4 Perimeter Seals, for Laboratory Testing Only—Seal the
centerline of the hangers to the test surface.
perimeter edges of the test specimen by one of the following
methods:
6. Type A Mounting
7.4.1 Cover with tape, caulking compound, or a similar
product as shown in Fig. 2.
6.1 Lay the test specimen directly against the test surface as
7.4.2 Cover with a wood or metal frame so that the top
shown in Fig. 1.
surface of the frame is flush with the front face of the test
6.2 Do not use an adhesive that is likely to leave a thin air
specimen as shown in Fig. 2. Minimize air spaces between the
space behind the test specimen. However, mechanical
frame and the perimeter edge of the test specimen. Air gaps
fasteners, carpet tape, or contact cement may be used to hold
between the bottom of the frame and the test surface shall be
the specimen against a vertical or overhead surface or to keep
sealed with duct tape or caulking.
the specimen in contact with the floor.
NOTE 2—The Type B mounting is intended to simulate acoustical
6.3 Iftwoormorepiecesofmaterial(orseparatepanels)are
ceiling tiles or other sound-absorptive products adhered to a hard surface
butted together to form the test specimen, it may be advisable
with an adhesive. In normal use, this method of application leaves a thin
to cover the joints between adjacent pieces with tape, caulking
air space between the product and the surface to which it is adhered. The
compound, or other material that is not sound absorptive. If the 3-mm ( ⁄8-in.) thick hardboard shims are used to control the depth of the
FIG. 1 Type A Mounting
E795 − 05 (2012)
FIG. 2 Typical Edge Seals
FIG. 3 Type B Mounting
air space during laboratory tests and should not be included in a normal
porous material attached to wood furring strips spaced 600 mm
installation.
(24 in.) on centers and laid directly against the test surface as
shown in Fig. 4. The suffix of the mounting designation shall
8. Type C Mounting
be the actual thickness of the furring strips rounded to the
8.1 The test specimen shall comprise sound-absorptive ma-
nearest integral multiple of 5 mm.
terial behind a perforated, expanded, open facing, or other
E795 − 05 (2012)
FIG. 4 Type C Mounting
3 1
NOTE 4—The preferred size for furring strips is 20 by 40 mm ( ⁄4 by 1 ⁄2
8.1.1 The length of the furring strips described in 8.1 shall
in.). This is a D20 mounting.
be shorter than the length of the test specimen by an amount
NOTE 5—If a different on center spacing of the wood furring strips is
equal to twice the width of the furring strips. This will allow
used, the spacing shall be noted in the report.
the placement of a furring strip at each end of the system to act
as an “end cap” and completely enclose the airspace below the 10. Type E Mounting
test specimen.
10.1 Mount the test specimen in a fixture that supports the
8.2 Perimeter Seals, for Laboratory Testing Only—The exposed face of the specimen at a designated distance from the
perimeter furring strips of the test specimen shall be sealed to test surface as shown in Fig. 6. The suffix of the mounting
the test surface with tape or caulking compound. designation shall be the distance between the exposed face of
the specimen and the test surface rounded to the nearest
NOTE 3—The preferred sizes for furring strips are 20 by 40 mm ( ⁄4 by
1 1 1 integral multiple of 5 mm.
1 ⁄2 in.) or 40 by 40 mm (1 ⁄2 by 1 ⁄2 in.), which corresponds to a C-20 or
C-40 mounting.
10.2 Mounting Fixture for Laboratory Testing Only—The
mounting fixture shall satisfy the following requirements:
9. Type D Mounting
10.2.1 The mounting fixture, test specimen, and test surface
9.1 Attachthetestspecimentowoodfurringstripsspacedat
shall enclose an air space that has no interior partitions.
300 mm (12 in.) on centers and laid directly against the test
10.2.2 The joint between the fixture and the test surface
surface as shown in Fig. 5. The suffix of the mounting
shall be sealed to prevent air leaks between the enclosed space
designation shall be the actual thickness of the furring strips
and the outside.
rounded to the nearest integral multiple of 5 mm.
10.2.3 The fixture shall include a rigid grid system that
9.1.1 The length of the furring strips described in 9.1 shall
supports the exposed face of the test specimen at the required
be shorter than the length of the test specimen by an amount
distance from the test surface. The distance from the exposed
equal to twice the width of the furring strips. This will allow
face of the test specimen (excluding decorative features) to the
the placement of a furring strip at each end of the system to act
test surface shall not vary by more than 5 mm (0.20 in.), across
as an “end cap” and completely enclose the airspace below the
the entire face of the specimen.
test specimen.
10.2.4 The fixture shall seal the perimeter edges of the test
specimen, and the top surface of the fixture shall be flush with
9.2 Perimeter Seals, for Laboratory Testing Only—Seal the
the front face of the test specimen as shown in Fig. 6.
perimeter edges of the test specimen by one of the following
10.2.5 The mounting fixture shall be made of a sturdy
methods:
material, such as 20-mm ( ⁄4-in.) thick plywood or 3-mm
9.2.1 Cover with tape, caulking compound, or a similar
( ⁄8-in.) thick aluminum.
product as shown in Fig. 2.
10.2.6 If a grid system is placed between the panels, on the
9.2.2 Cover with a wood or metal frame so that the top
exposed side of the specimen, the grid size and arrangement
surface of the frame is flush with the front face of the test
shall be noted in the report.
specimen as shown in Fig. 2. Minimize air spaces between the
frame and the perimeter edge of the test specimen. Air gaps
NOTE 6—Type E mountings are intended to simulate a suspended
between the bottom of the frame and the test surface shall be
ceiling with an open plenum above it.
sealed with duct tape or caulking. NOTE 7—When there is good reason to test on aType E mounting other
FIG. 5 Type D Mounting
E795 − 05 (2012)
FIG. 6 Type E Mounting
than Type E-400, a mounting whose suffix is an integral multiple of 25 is
absorptive.Ifthejointsaresealedinthismanner,thetestreport
preferred (for example, E-375, E-425, and so forth).
shall describe the method of sealing.
NOTE 8—It has been found that if a gasket is used between the test
fixture and the test surface, placing the gasket so that it is flush with the 11.3 Perimeter Seals for Laboratory Testing Only—If the
exterior surface of the test fixture will minimized the variability in results.
perimeter edges of the test specimen are not exposed in normal
use, seal them by one of the following two methods:
11. Type F Mounting
11.3.1 Cover with tape, caulking compound, or a similar
11.1 Lay the test specimen with spacers against the test
product as shown in Fig. 2.
surface as shown in Fig. 7.
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