1、Designation: E 795 05Standard Practices forMounting Test Specimens During Sound Absorption Tests1This standard is issued under the fixed designation E 795; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision.
2、A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 These practices cover test specimen mountings to be
3、used during sound absorption tests performed in accordancewith Test Method C 423.1.2 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.2. Referenced Documents2.1 ASTM Standards:2C 423 Test Method for Sound Absorption and Sound Ab
4、-sorption Coefficients by the Reverberation Room MethodC 634 Terminology Relating to Environmental Acoustics2.2 ISO Standard:ISO 354 Measurement of SoundAbsorption in a Reverbera-tion Room33. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 Except as noted in 4.2, the terms used i
5、n thesepractices are defined in Terminology C 634.3.2 The following terms have the meaning noted for thesepractices only:3.2.1 sound-absorbing units consists of test specimensthat are in direct contact with or suspended from ceilings,walls, or other room surfaces. Sound-absorbing units include,but a
6、re not limited to, baffles, draperies, space absorbers,volume absorbers (bass traps), and other three-dimensionalobjects.3.2.2 test surfaceany hard surface over which the testspecimen or test specimen mounting is placed for testing inaccordance with Test Method C 423. The surface shall satisfythe ro
7、om construction requirements of Test Method C 423.Inmost cases, the surface will be the floor of the reverberationroom.4. Significance and Use4.1 The sound absorption of a material that covers a flatsurface depends not only on the physical properties of thematerial but also on the way in which the m
8、aterial is mountedover the surface. The mountings specified in these practices areintended to simulate in the laboratory conditions that exist innormal use.4.2 Some of the specified mountings require special fixturesor minor deviations from normal practice. These fixtures ordeviations are to be used
9、 only during laboratory tests andshould not be specified for practical installations. They arenoted in the specifications for the mountings in question by thephrase “for laboratory testing only.”4.3 Test reports may refer to these mountings by typedesignation instead of providing a detailed descript
10、ion of themounting used.5. Classification5.1 The mountings are designated as follows:5.1.1 Type A MountingTest specimen laid directly againstthe test surface (described in detail in Section 6).5.1.2 Type B MountingTest specimen cemented to gyp-sum board and laid directly against the test surface (de
11、scribedin detail in Section 7).5.1.3 Type C MountingTest specimen comprising sound-absorptive material behind a perforated, expanded, open facingor other porous material (described in detail in Section 8).5.1.4 Type D MountingTest specimen mounted on woodfurring strips (described in detail in Sectio
12、n 9).5.1.5 Type E MountingTest specimen mounted with an airspace behind it (described in detail in Section 10).5.1.6 Type F MountingTest specimen mounted with an airspace behind it (described in detail in Section 11).1These practices are under the jurisdiction of ASTM Committee E33 onBuilding and En
13、vironmental Acoustics and are the direct responsibility of Subcom-mittee E33.01 on Sound Absorption.Current edition approved Oct. 15, 2005. Published December 2005. Originallyapproved in 1981. Last previous edition approved in 2000 as E 795 00.2For referenced ASTM standards, visit the ASTM website,
14、www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036.1Copyright
15、 ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5.1.7 Type G MountingTest specimen is a drapery, win-dow shade, or blind hung parallel to the test surface (describedin detail in Section 12).5.1.8 Type H MountingTest specimen is a drapery sus-p
16、ended away from any vertical surface (described in detail inSection 13).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
17、 units (described indetail in Section 15).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 withconcrete blocks or block-like specimens that are normallyassembled using mortar (described in detail in Section 17).
18、5.1.13 Type M MountingTest specimen is theater seats, (described in detail in Section 18).5.2 Type C, D, E, and G mountings are further designatedby a numerical suffix which indicates the distance (in millime-tres) from the specimen to the test surface rounded to thenearest integral multiple of 5 mm
19、. For example, a Type E-400mounting is a plenum mounting in which the face of the testspecimen is 400 mm (1534 in.) away from the test surface. Thedistances specified by the suffixes are as follows:5.2.1 For a Type C MountingThe thickness of the furringstrips.5.2.2 For a Type D MountingThe thickness
20、 of the furringstrips.5.2.3 For a Type E MountingThe distance from theexposed 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 thecenterline of the hangers to the test surface.6. Type A Mounting6.1 Lay
21、the test specimen directly against the test surface asshown in Fig. 1.6.2 Do not use an adhesive that is likely to leave a thin airspace behind the test specimen. However, mechanical fasten-ers, carpet tape, or contact cement may be used to hold thespecimen against a vertical or overhead surface or
22、to keep thespecimen in contact with the floor.6.3 If two or more pieces of material (or separate panels) arebutted together to form the test specimen, it may be advisableto cover the joints between adjacent pieces with tape, caulkingcompound, or other material that is not sound absorptive. If thejoi
23、nts are sealed in this manner, the test report shall describethe method of sealing.6.4 Perimeter Seals for Laboratory Testing OnlyIf theperimeter edges of the test specimen are not exposed in normaluse, seal them by one of the following two methods:6.4.1 Cover with tape, caulking compound, or a simi
24、larproduct as shown in Fig. 2.6.4.2 Cover with a wood or metal frame so that the topsurface of the frame is flush with the front face of the testspecimen as shown in Fig. 2. Minimize air spaces between theframe and the perimeter edge of the test specimen. Air gapsbetween the bottom of the frame and
25、the test surface shall besealed with duct tape or caulking.NOTE 1The Type A mounting is intended to simulate normal usewhere a product, such as carpet, wall panels, or ceiling tile is either laiddirectly on the floor or attached to a wall or ceiling with adhesive ormechanical fasteners. Panels or ti
26、les arranged as independent units, that is,not butted together at the edges to form a single extended plane, are to betested as a Type J mounting.7. Type B Mounting7.1 Adhere the test specimen to gypsum board laid directlyagainst the test surface as shown in Fig. 3. The thickness of thegypsum board
27、is not critical.7.2 Apply the adhesive in accordance with the manufactur-ers instructions. If there are no specific instructions, apply fourdaubs of adhesive to the back of each piece of the testspecimen.7.3 For Laboratory Testing OnlyPlace 3 by 25 by 25-mm(18 by 1 by 1-in.) hardboard shims between
28、the test specimenand the gypsum board at the four corners of each piece of testspecimen.7.4 Perimeter Seals, for Laboratory Testing OnlySeal theperimeter edges of the test specimen by one of the followingmethods:7.4.1 Cover with tape, caulking compound, or a similarproduct as shown in Fig. 2.7.4.2 C
29、over with a wood or metal frame so that the topsurface of the frame is flush with the front face of the testspecimen as shown in Fig. 2. Minimize air spaces between theframe and the perimeter edge of the test specimen. Air gapsbetween the bottom of the frame and the test surface shall besealed with
30、duct tape or caulking.NOTE 2The Type B mounting is intended to simulate acousticalceiling tiles or other sound-absorptive products adhered to a hard surfacewith an adhesive. In normal use, this method of application leaves a thinair space between the product and the surface to which it is adhered. T
31、he3-mm (18-in.) thick hardboard shims are used to control the depth of theair space during laboratory tests and should not be included in a normalinstallation.8. Type C Mounting8.1 The test specimen shall comprise sound-absorptive ma-terial behind a perforated, expanded, open facing, or otherporous
32、material attached to wood furring strips spaced 600 mm(24 in.) on centers and laid directly against the test surface asshown in Fig. 4. The suffix of the mounting designation shallbe the actual thickness of the furring strips rounded to thenearest integral multiple of 5 mm.8.1.1 The length of the fu
33、rring strips described in 8.1 shallbe shorter than the length of the test specimen by an amountequal to twice the width of the furring strips. This will allowthe placement of a furring strip at each end of the system to actas an “end cap” and completely enclose the airspace below thetest specimen.8.
34、2 Perimeter Seals, for Laboratory Testing OnlyTheperimeter furring strips of the test specimen shall be sealed tothe test surface with tape or caulking compound.NOTE 3The preferred sizes for furring strips are 20 by 40 mm (34 byE795052112 in.) or 40 by 40 mm (112 by 112 in.), which corresponds to a
35、C-20 orC-40 mounting.9. Type D Mounting9.1 Attach the test specimen to wood furring strips spaced at300 mm (12 in.) on centers and laid directly against the testsurface as shown in Fig. 5. The suffix of the mountingdesignation shall be the actual thickness of the furring stripsrounded to the nearest
36、 integral multiple of 5 mm.9.1.1 The length of the furring strips described in 9.1 shallbe shorter than the length of the test specimen by an amountequal to twice the width of the furring strips. This will allowthe placement of a furring strip at each end of the system to actas an “end cap” and comp
37、letely enclose the airspace below thetest specimen.9.2 Perimeter Seals, for Laboratory Testing OnlySeal theperimeter edges of the test specimen by one of the followingmethods:9.2.1 Cover with tape, caulking compound, or a similarproduct as shown in Fig. 2.9.2.2 Cover with a wood or metal frame so th
38、at the topsurface of the frame is flush with the front face of the testspecimen as shown in Fig. 2. Minimize air spaces between theframe and the perimeter edge of the test specimen. Air gapsbetween the bottom of the frame and the test surface shall besealed with duct tape or caulking.NOTE 4The prefe
39、rred size for furring strips is 20 by 40 mm (34 by 112in.). This is a D20 mounting.NOTE 5If a different on center spacing of the wood furring strips isused, the spacing shall be noted in the report.10. Type E Mounting10.1 Mount the test specimen in a fixture that supports theexposed face of the spec
40、imen at a designated distance from thetest surface as shown in Fig. 6. The suffix of the mountingdesignation shall be the distance between the exposed face ofthe specimen and the test surface rounded to the nearestintegral multiple of 5 mm.10.2 Mounting Fixture for Laboratory Testing OnlyThemounting
41、 fixture shall satisfy the following requirements:10.2.1 The mounting fixture, test specimen, and test surfaceshall enclose an air space that has no interior partitions.10.2.2 The joint between the fixture and the test surfaceshall be sealed to prevent air leaks between the enclosed spaceand the out
42、side.10.2.3 The fixture shall include a rigid grid system thatsupports the exposed face of the test specimen at the requireddistance from the test surface. The distance from the exposedface of the test specimen (excluding decorative features) to thetest surface shall not vary by more than 5 mm (0.20
43、 in.), acrossthe entire face of the specimen.10.2.4 The fixture shall seal the perimeter edges of the testspecimen, and the top surface of the fixture shall be flush withthe front face of the test specimen as shown in Fig. 6.10.2.5 The mounting fixture shall be made of a sturdymaterial, such as 20-m
44、m (34-in.) thick plywood or 3-mm(18-in.) thick aluminum.10.2.6 If a grid system is placed between the panels, on theexposed side of the specimen, the grid size and arrangementshall be noted in the report.NOTE 6Type E mountings are intended to simulate a suspendedceiling with an open plenum above it.
45、NOTE 7When there is good reason to test on a Type E mounting otherthan Type E-400, a mounting whose suffix is an integral multiple of 25 ispreferred (for example, E-375, E-425, and so forth).NOTE 8It has been found that if a gasket is used between the testfixture and the test surface, placing the ga
46、sket so that it is flush with theexterior surface of the test fixture will minimized the variability in results.11. Type F Mounting11.1 Lay the test specimen with spacers against the testsurface as shown in Fig. 7. If spacers are not an integral part ofthe specimen then metal furring, solid wood blo
47、cks, or similaritems may be used to space the product away from the testsurface. The suffix of the mounting designation shall be theactual thickness of the spacers rounded to the nearest integralmultiple of 5 mm for spacers 10 mm thick or greater and to thenearest integral multiple of 1 mm for those
48、 less than 10 mm.NOTE 9Any specimen with a spacer less than 1 mm shall be testedand reported as Type A mounting.11.2 If two or more pieces of material (or separate panels)are butted together to form the test specimen, it may beadvisable to cover the joints between adjacent pieces with tape,caulking
49、compound, or other material that is not soundabsorptive. If the joints are sealed in this manner, the test reportshall describe the method of sealing.11.3 Perimeter Seals for Laboratory Testing OnlyIf theperimeter edges of the test specimen are not exposed in normaluse, seal them by one of the following two methods:11.3.1 Cover with tape, caulking compound, or a similarproduct as shown in Fig. 2.11.3.2 Cover with a wood or metal frame so that the topsurface of the frame is flush with the front face of the testspecimen as shown in Fig. 2
