1、Designation: E795 05 (Reapproved 2012)E795 16Standard Practices forMounting Test Specimens During Sound Absorption Tests1This standard is issued under the fixed designation E795; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the
2、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.This standard has been approved for use by agencies of the U.S. Department of Defense.1. Scope1.1 These practices cover te
3、st specimen mountings to be used during sound absorption tests performed in accordance with TestMethod 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.2. Referenced Documents2.1 ASTM Standards:2C423 Test Method for S
4、ound Absorption and Sound Absorption Coefficients by the Reverberation Room MethodC634 Terminology Relating to Building and Environmental Acoustics2.2 ISO Standard:ISO 354 Measurement of Sound Absorption in a Reverberation Room33. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 E
5、xcept as noted in 4.2, the terms used in these practices are defined in Terminology C634.3.2 The following terms have the meaning noted for these practices only:3.2.1 sound-absorbing units consists of test specimens that are in direct contact with or suspended from ceilings, walls, orother room surf
6、aces. Sound-absorbing units include, but are not limited to, baffles, draperies, space absorbers, volume absorbers(bass traps), and other three-dimensional objects.3.2.2 test surfaceany hard surface over which the test specimen or test specimen mounting is placed for testing in accordancewith Test M
7、ethod C423. The surface shall satisfy the room construction requirements of Test Method C423. In most cases, thesurface will be the floor of the reverberation room.4. Significance and Use4.1 The sound absorption of a material that covers a flat surface depends not only on the physical properties of
8、the material butalso on the way in which the material is mounted over the surface. The mountings specified in these practices are intended tosimulate in the laboratory conditions that exist in normal use.4.2 Some of the specified mountings require special fixtures or minor deviations from normal pra
9、ctice. These fixtures ordeviations are to be used only during laboratory tests and should not be specified for practical installations. They are noted in thespecifications for the mountings in question by the phrase “for laboratory testing only.”4.3 Test reports may refer to these mountings by type
10、designation instead of providing a detailed description of the mountingused.5. Classification5.1 The mountings are designated as follows:5.1.1 Type A MountingTest specimen laid directly against the test surface (described in detail in Section 6).1 These practices are under the jurisdiction of ASTM C
11、ommittee E33 on Building and Environmental Acoustics and are the direct responsibility of Subcommittee E33.01on Sound Absorption.Current edition approved Sept. 1, 2012May 15, 2016. Published November 2012June 2016. Originally approved in 1981. Last previous edition approved in 20052012 asE795 05.E79
12、5 05 (2012). DOI: 10.1520/E0795-05R12.10.1520/E0795-16.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3 Avai
13、lable from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technic
14、ally possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box
15、 C700, West Conshohocken, PA 19428-2959. United States15.1.2 Type B MountingTest specimen cemented to gypsum board and laid directly against the test surface (described in detailin Section 7).5.1.3 Type C MountingTest specimen comprising sound-absorptive material behind a perforated, expanded, open
16、facing orother porous material (described in detail in Section 8).5.1.4 Type D MountingTest specimen mounted on wood furring strips (described in detail in Section 9).5.1.5 Type E MountingTest specimen mounted with an air space behind it (described in detail in Section 10).5.1.6 Type F MountingTest
17、specimen mounted with an air space behind it (described in detail in Section 11).5.1.7 Type G MountingTest specimen is a drapery, window shade, or blind hung parallel to the test surface (described in detailin Section 12).5.1.8 Type H MountingTest specimen is a drapery suspended away from any vertic
18、al surface (described in detail in Section13).5.1.9 Type I MountingThe specimen is a spray- or trowel-applied material on an acoustically hard substrate (described indetail in Section 14).5.1.10 Type J MountingThe specimen is a sound-absorbing unit or set of sound-absorbing units (described in detai
19、l in Section15).5.1.11 Type K MountingTest specimen is an office screen (described in detail in Section 16).5.1.12 Type L MountingThis mounting is for use with concrete blocks or block-like specimens that are normally assembledusing mortar (described in detail in Section 17).5.1.13 Type M MountingTe
20、st specimen is theater seats, ( described (described in detail in Section 18).5.2 Type C, D, E, and G mountings are further designated by a numerical suffix which indicates the distance (in millimetres)from the specimen to the test surface rounded to the nearest integral multiple of 5 mm. For exampl
21、e, a Type E-400 mounting isa plenum mounting in which the face of the test specimen is 400 mm (1534 in.) away from the test surface. The distances specifiedby the suffixes are as follows:5.2.1 For a Type C MountingThe thickness of the furring strips.5.2.2 For a Type D MountingThe thickness of the fu
22、rring strips.5.2.3 For a Type E MountingThe distance from the exposed face of the test specimen to the test surface.5.2.4 For a Type F MountingThe thickness of the spacers.5.2.5 For a Type G MountingThe distance from the centerline of the hangers to the test surface.6. Type A Mounting6.1 Lay the tes
23、t specimen directly against the test surface as shown in Fig. 1.6.2 Do not use an adhesive that is likely to leave a thin air space behind the test specimen. However, mechanical fasteners,carpet tape, or contact cement may be used to hold the specimen against a vertical or overhead surface or to kee
24、p the specimenin contact with the floor.6.3 If two or more pieces of material (or separate panels) are butted together to form the test specimen, it may be advisable tocover the joints between adjacent pieces with tape, caulking compound, or other material that is not sound absorptive. If the joints
25、are sealed in this manner, the test report shall describe the method of sealing.6.4 Perimeter Seals for Laboratory Testing OnlyIf the perimeter edges of the test specimen are not exposed in normal use,seal them by one of the following two methods:6.4.1 Cover with tape, caulking compound, or a simila
26、r product as shown in Fig. 2.6.4.2 Cover with a wood or metal frame so that the top surface of the frame is flush with the front face of the test specimenas shown in Fig. 2. Minimize air spaces between the frame and the perimeter edge of the test specimen. Air gaps between thebottom of the frame and
27、 the test surface shall be sealed with duct tape or caulking.NOTE 1The Type A mounting is intended to simulate normal use where a product, such as carpet, wall panels, or ceiling tile is either laid directlyon the floor or attached to a wall or ceiling with adhesive or mechanical fasteners. Panels o
28、r tiles arranged as independent units, that is, not butted togetherat the edges to form a single extended plane, are to be tested as a Type J mounting.7. Type B Mounting7.1 Adhere the test specimen to gypsum board laid directly against the test surface as shown in Fig. 3. The thickness of thegypsum
29、board is not critical.7.2 Apply the adhesive in accordance with the manufacturers instructions. If there are no specific instructions, apply four daubsof adhesive to the back of each piece of the test specimen.7.3 For Laboratory Testing OnlyPlace 3 by 25 by 25-mm (18 by 1 by 1-in.) hardboard shims b
30、etween the test specimen andthe gypsum board at the four corners of each piece of test specimen.7.4 Perimeter Seals, for Laboratory Testing OnlySeal the perimeter edges of the test specimen by one of the followingmethods:E795 1627.4.1 Cover with tape, caulking compound, or a similar product as shown
31、 in Fig. 2.7.4.2 Cover with a wood or metal frame so that the top surface of the frame is flush with the front face of the test specimenas shown in Fig. 2. Minimize air spaces between the frame and the perimeter edge of the test specimen. Air gaps between thebottom of the frame and the test surface
32、shall be sealed with duct tape or caulking.NOTE 2The Type B mounting is intended to simulate acoustical ceiling tiles or other sound-absorptive products adhered to a hard surface with anadhesive. In normal use, this method of application leaves a thin air space between the product and the surface to
33、 which it is adhered. The 3-mm (18-in.)thick hardboard shims are used to control the depth of the air space during laboratory tests and should not be included in a normal installation.8. Type C Mounting8.1 The test specimen shall comprise sound-absorptive material behind a perforated, expanded, open
34、 facing, or other porousmaterial attached to wood furring strips spaced 600 mm (24 in.) on centers and laid directly against the test surface as shown inFig. 4. The suffix of the mounting designation shall be the actual thickness of the furring strips rounded to the nearest integralmultiple of 5 mm.
35、8.1.1 The length of the furring strips described in 8.1 shall be shorter than the length of the test specimen by an amount equalto twice the width of the furring strips. This will allow the placement of a furring strip at each end of the system to act as an “endcap” and completely enclose the airspa
36、ce below the test specimen.8.2 Perimeter Seals, for Laboratory Testing OnlyThe perimeter furring strips of the test specimen shall be sealed to the testsurface with tape or caulking compound.NOTE 3The preferred sizes for furring strips are 20 by 40 mm (34 by 112 in.) or 40 by 40 mm (112 by 112 in.),
37、 which corresponds to a C-20 or C-40mounting.9. Type D Mounting9.1 Attach the test specimen to wood furring strips spaced at 300 mm (12 in.) on centers and laid directly against the test surfaceas shown in Fig. 5. The suffix of the mounting designation shall be the actual thickness of the furring st
38、rips rounded to the nearestintegral multiple of 5 mm.9.1.1 The length of the furring strips described in 9.1 shall be shorter than the length of the test specimen by an amount equalto twice the width of the furring strips. This will allow the placement of a furring strip at each end of the system to
39、 act as an “endcap” and completely enclose the airspace below the test specimen.9.2 Perimeter Seals, for Laboratory Testing OnlySeal the perimeter edges of the test specimen by one of the followingmethods:9.2.1 Cover with tape, caulking compound, or a similar product as shown in Fig. 2.9.2.2 Cover w
40、ith a wood or metal frame so that the top surface of the frame is flush with the front face of the test specimenas shown in Fig. 2. Minimize air spaces between the frame and the perimeter edge of the test specimen. Air gaps between thebottom of the frame and the test surface shall be sealed with duc
41、t tape or caulking.NOTE 4The preferred size for furring strips is 20 by 40 mm (34 by 112 in.). This is a D20 mounting.NOTE 5If a different on center spacing of the wood furring strips is used, the spacing shall be noted in the report.10. Type E Mounting10.1 Mount the test specimen in a fixture that
42、supports the exposed face of the specimen at a designated distance from the testsurface as shown in Fig. 6. The suffix of the mounting designation shall be the distance between the exposed face of the specimenand the test surface rounded to the nearest integral multiple of 5 mm.10.2 Mounting Fixture
43、 for Laboratory Testing OnlyThe mounting fixture shall satisfy the following requirements:10.2.1 The mounting fixture, test specimen, and test surface shall enclose an air space that has no interior partitions.10.2.2 The joint between the fixture and the test surface shall be sealed to prevent air l
44、eaks between the enclosed space and theoutside.10.2.3 The fixture shall include a rigid grid system that supports the exposed face of the test specimen at the required distancefrom the test surface. The distance from the exposed face of the test specimen (excluding decorative features) to the test s
45、urfaceshall not vary by more than 5 mm (0.20 in.), across the entire face of the 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 thefront face of the test specimen as shown in Fig. 6.10.2.5 The mounting fixture s
46、hall be made of a sturdy material, such as 20-mm (34-in.) thick plywood or 3-mm (18-in.) thickaluminum.10.2.6 If a grid system is placed between the panels, on the exposed side of the specimen, the grid size and arrangement shallbe noted in the report.NOTE 6Type E mountings are intended to simulate
47、a suspended ceiling with an open plenum above it.NOTE 7When there is good reason to test on a Type E mounting other than Type E-400, a mounting whose suffix is an integral multiple of 25 ispreferred (for example, E-375, E-425, and so forth).E795 163NOTE 8It has been found that if a gasket is used be
48、tween the test fixture and the test surface, placing the gasket so that it is flush with the exteriorsurface of the test fixture will minimized the variability in results.11. Type F Mounting11.1 Lay the test specimen with spacers against the test surface as shown in Fig. 7. If spacers are not an int
49、egral part of thespecimen then metal furring, solid wood blocks, or similar items may be used to space the product away from the test surface. Thesuffix of the mounting designation shall be the actual thickness of the spacers rounded to the nearest integral multiple of 5 mmfor spacers 10 mm thick or greater and to the nearest integral multiple of 1 mm for those less than 10 mm.NOTE 9Any specimen with a spacer less than 1 mm shall be tested and reported as Type A mounting.11.2 If two or more pieces of material (or separate panels)
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