ASTM E492-09(2016)e1

Standard Test Method for Laboratory Measurement of Impact Sound Transmission Through Floor-Ceiling Assemblies Using the Tapping Machine

SIGNIFICANCE AND USE
5.1 The spectrum of the noise in the room below the test specimen is determined by the following:  
5.1.1 The size and the mechanical properties of the floor-ceiling assembly, such as its construction, surface, mounting or edge restraints, stiffness, or internal damping,  
5.1.2 The acoustical response of the room below,  
5.1.3 The placement of the object or device producing the impacts, and  
5.1.4 The nature of the actual impact itself.  
5.2 This test method is based on the use of a standardized tapping machine of the type specified in 8.1 placed in specific positions on the floor. This machine produces a continuous series of uniform impacts at a uniform rate on a test floor and generates in the receiving room broadband sound pressure levels that are sufficiently high to make measurements possible beneath most floor types even in the presence of background noise. The tapping machine itself, however, is not designed to simulate any one type of impact, such as produced by male or female footsteps.  
5.3 Because of its portable design, the tapping machine does not simulate the weight of a human walker. Therefore, the structural sounds, i.e., creaks or booms of a floor assembly caused by such footstep excitation is not reflected in the single number impact rating derived from test results obtained by this test method. The degree of correlation between the results of tapping machine tests in the laboratory and the subjective acceptance of floors under typical conditions of domestic impact excitation is uncertain. The correlation will depend on both the type of floor construction and the nature of the impact excitation in the building.  
5.4 In laboratories designed to satisfy the requirements of this test method, the intent is that only significant path for sound transmission between the rooms is through the test specimen. This is not generally the case in buildings where there are often many other paths for sounds— flanking sound transmission. Consequently so...
SCOPE
1.1 This test method covers the laboratory measurement of impact sound transmission of floor-ceiling assemblies using a standardized tapping machine. It is assumed that the test specimen constitutes the primary sound transmission path into a receiving room located directly below and that a good approximation to a diffuse sound field exists in this room.  
1.2 Measurements may be conducted on floor-ceiling assemblies of all kinds, including those with floating-floor or suspended ceiling elements, or both, and floor-ceiling assemblies surfaced with any type of floor-surfacing or floor-covering materials.  
1.3 This test method prescribes a uniform procedure for reporting laboratory test data, that is, the normalized one-third octave band sound pressure levels transmitted by the floor-ceiling assembly due to the tapping machine.  
1.4 Laboratory Accreditation—The requirements for accrediting a laboratory for performing this test method are given in Annex A2.  
1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.6 This standard does not purport to address 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.

General Information

• Status: Historical
• Publication Date: 31-Mar-2016
• ICS: 91.120.20 - Acoustics in building. Sound insulation
• Technical Committee: E33 - Building and Environmental Acoustics
• Drafting Committee: E33.10 - Structural Acoustics and Vibration

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
´1
Designation: E492 − 09 (Reapproved 2016)
Standard Test Method for
Laboratory Measurement of Impact Sound Transmission
Through Floor-Ceiling Assemblies Using the Tapping
Machine
This standard is issued under the fixed designation E492; 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.
ε NOTE—Editorially corrected 14.1 in April 2016.
INTRODUCTION
This test method is one of several for evaluating the sound insulating properties of building
elements. It is designed to measure the impact sound transmission performance of an isolated
floor-ceiling assembly, in a controlled laboratory environment. Others in the set deal with field
measurement of impact sound transmission through floor-ceiling assemblies (Test Method E1007),
measurement of sound isolation in buildings (Test Method E336), the measurement of sound
transmission through a common plenum between two rooms (Test Method E1414), and the laboratory
measurement of airborne sound transmission loss of building partitions such as walls, floor-ceiling
assemblies, doors, and other space-dividing elements (Test Method E90).
1. Scope 1.5 The values stated in SI units are to be regarded as
standard. No other units of measurement are included in this
1.1 This test method covers the laboratory measurement of
standard.
impact sound transmission of floor-ceiling assemblies using a
1.6 This standard does not purport to address the safety
standardized tapping machine. It is assumed that the test
concerns, if any, associated with its use. It is the responsibility
specimen constitutes the primary sound transmission path into
of the user of this standard to establish appropriate safety and
a receiving room located directly below and that a good
health practices and determine the applicability of regulatory
approximation to a diffuse sound field exists in this room.
limitations prior to use.
1.2 Measurements may be conducted on floor-ceiling as-
2. Referenced Documents
semblies of all kinds, including those with floating-floor or
suspended ceiling elements, or both, and floor-ceiling assem-
2.1 ASTM Standards:
blies surfaced with any type of floor-surfacing or floor-
C423 Test Method for SoundAbsorption and SoundAbsorp-
covering materials.
tion Coefficients by the Reverberation Room Method
C634 Terminology Relating to Building and Environmental
1.3 This test method prescribes a uniform procedure for
Acoustics
reporting laboratory test data, that is, the normalized one-third
E90 Test Method for Laboratory Measurement of Airborne
octave band sound pressure levels transmitted by the floor-
Sound Transmission Loss of Building Partitions and
ceiling assembly due to the tapping machine.
Elements
E336 Test Method for Measurement of Airborne Sound
1.4 Laboratory Accreditation—The requirements for ac-
Attenuation between Rooms in Buildings
crediting a laboratory for performing this test method are given
E989 Classification for Determination of Impact Insulation
in Annex A2.
Class (IIC)
E1007 Test Method for Field Measurement of Tapping
ThistestmethodisunderthejurisdictionofASTMCommitteeE33onBuilding
and Environmental Acoustics and is the direct responsibility of Subcommittee
E33.10 on Vibration. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved April 1, 2016. Published April 2016. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 1973. Last previous edition approved in 2009 as E492 – 09. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/E0492-09R16E01. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
´1
E492 − 09 (2016)
Machine Impact Sound Transmission Through Floor- the tapping machine is measured in the receiving room below
Ceiling Assemblies and Associated Support Structures in one-third octave bands.
E1414 Test Method for Airborne Sound Attenuation Be-
4.2 Since the spectrum depends on the absorption of the
tween Rooms Sharing a Common Ceiling Plenum
receiving room, the sound pressure levels are normalized to a
E2235 Test Method for Determination of Decay Rates for
reference absorption for purposes of comparing results ob-
Use in Sound Insulation Test Methods
tained in different receiving rooms that differ in absorption.
2.2 ANSI Standards:
S1.10 Pressure Calibration of Laboratory Standard Pressure
5. Significance and Use
Microphones
5.1 The spectrum of the noise in the room below the test
S1.11 Specification for Octave-Band and Fractional-Octave-
specimen is determined by the following:
Band Analog and Digital Filters
5.1.1 The size and the mechanical properties of the floor-
S1.43 Specification for Integrating-Averaging Sound-Level
ceiling assembly, such as its construction, surface, mounting or
Meters
edge restraints, stiffness, or internal damping,
S12.51 Acoustics—Determination of Sound Power Levels
5.1.2 The acoustical response of the room below,
of Noise Sources Using Sound Pressure—Precision Meth-
5.1.3 The placement of the object or device producing the
ods for Reverberation Rooms
impacts, and
2.3 ISO Standards:
5.1.4 The nature of the actual impact itself.
ISO 140/6 Acoustics—Measurement of Sound Insulation in
Buildings and of Building Elements Part 6: Laboratory 5.2 This test method is based on the use of a standardized
tapping machine of the type specified in 8.1 placed in specific
Measurements of Impact Sound Insulation of Floors
ISO 3741 Determination of Sound Power Levels of Noise positions on the floor. This machine produces a continuous
series of uniform impacts at a uniform rate on a test floor and
Sources Using Sound Pressure—Precision Methods for
Reverberation Rooms generates in the receiving room broadband sound pressure
levels that are sufficiently high to make measurements possible
2.4 IEC Standards:
beneath most floor types even in the presence of background
IEC 60942 Electroacoustics—Sound Calibrators
noise. The tapping machine itself, however, is not designed to
IEC 61672 Electroacoustics—Sound Level Meters—Part 1:
simulate any one type of impact, such as produced by male or
Specifications
female footsteps.
3. Terminology
5.3 Becauseofitsportabledesign,thetappingmachinedoes
not simulate the weight of a human walker. Therefore, the
3.1 The following terms used in this test method have
structural sounds, i.e., creaks or booms of a floor assembly
specific meanings that are defined in Terminology C634:
caused by such footstep excitation is not reflected in the single
airborne sound
number impact rating derived from test results obtained by this
average sound pressure level
background noise
test method. The degree of correlation between the results of
decay rate
tapping machine tests in the laboratory and the subjective
decibel
acceptance of floors under typical conditions of domestic
diffuse sound field
impact insulation class
impact excitation is uncertain. The correlation will depend on
one-third octave band
both the type of floor construction and the nature of the impact
receiving room
excitation in the building.
reverberant sound field
reverberation room
5.4 In laboratories designed to satisfy the requirements of
sound absorption
sound pressure level
this test method, the intent is that only significant path for
sound transmission between the rooms is through the test
3.2 Definitions of Terms Specific to This Standard:
specimen. This is not generally the case in buildings where
3.2.1 receiving room—a reverberation room below the floor
there are often many other paths for sounds— flanking sound
specimen under test in which the sound pressure levels due to
transmission. Consequently sound ratings obtained using this
the tapping machine are measured.
test method do not relate directly to sound isolation in
buildings; they represent an upper limit to what would be
4. Summary of Test Method
measured in a field test.
4.1 A standard tapping machine is placed in operation on a
floor specimen that is intended to represent a horizontal 5.5 This test method is not intended for field tests. Field
separation between two rooms, one directly above the other. tests are performed according to Test Method E1007.
Theaveragespectrumofthesoundpressurelevelsproducedby
6. Test Rooms
6.1 The test facility shall be so constructed and arranged
Available from American National Standards Institute (ANSI), 25 W. 43rd St.,
that the test specimen constitutes the only important transmis-
4th Floor, New York, NY 10036, http://www.ansi.org.
sion path for the tapping machine sound.
Available from International Electrotechnical Commission (IEC), 3 rue de
Varembé, Case postale 131, CH-1211, Geneva 20, Switzerland, http://www.iec.ch. NOTE 1—Common methods for ensuring that this requirement is
satisfied include mounting the specimen resiliently in the test opening,
´1
E492 − 09 (2016)
mounting the specimen in a resiliently supported test frame, and support-
test specimen shall be sealed to prevent tapping machine
ing rooms resiliently. In general, all rigid connections between the
operational sounds from entering the room below. The speci-
specimen and the test rooms should be avoided.
men shall be structurally isolated from the receiving room to
6.2 The spatial variations of sound pressure level measured
avoid significant transmission of vibration from the specimen
in the receiving room shall be such that the precision require-
through the supporting structure to the room below.
ments in Annex A1 are satisfied at all frequencies.
7.3 Floor-surfacing materials, such as vinyl, carpets and
6.3 Volume of Receiving Room—The recommended mini-
pads, especially when installed with adhesive, significantly
mum volume of the receiving room is 125 m .
affect the response of the test specimen to impacts, both during
NOTE 2—See Test Method E90 for recommendations for new construc-
test and in normal use. Consequently, such materials shall be
tion.
deemed parts of the test specimen. The materials and the
6.4 Room Absorption—The sound absorption in the receiv-
manner of installing them shall be fully described in the test
ing room should be low to achieve the best possible simulation
report. The floor-surfacing material shall cover the whole test
of the ideal diffuse field condition, and to minimize the region
specimen, not merely the portion under the impact machine.
dominated by the direct field of the test specimen. In the
1/3
frequency range that extends from f = 2000/V to 2000 Hz,
8. Tapping Machine
the absorption in the receiving room (as furnished with
8.1 This test method is based on the use of a standardized
diffusers) should be no greater than:
tapping machine that conforms to the following specifications:
2/3
A 5 V /3 (1)
8.1.1 The tapping machine shall be motor-driven.
where: 8.1.2 The tapping machine shall have five hammers equally
spaced in a line. The distance between centerlines of neigh-
V = the room volume, m , and
boring hammers shall be 100 6 3 mm.
A = the sound absorption of the room, m .
8.1.3 Each hammer shall have an effective mass of 500 6 6
1/3
6.4.1 For frequencies below f = 2000/V , somewhat higher
g and shall fall freely from a height of 40 6 3 mm.
absorption may be desirable to accommodate requirements of
8.1.4 The falling direction of the hammers shall be perpen-
other test methods (for example, ISO 3741); in any case, the
dicular to the test surface to within 6 0.5°.
absorption should be no greater than three times the value
8.1.5 The part of the hammer carrying the impact surface
given by Eq 1.
shall be cylindrical with a diameter of 30 6 0.2 mm.
NOTE 3—For frequencies above 2000 Hz, atmospheric absorption may
8.1.6 Theimpactsurfaceshallbeofhardenedsteelandshall
make it impossible to avoid a slightly higher value than that given in Eq
1.
be approximately spherical with a curvature radius of 500 6
100 mm.
6.5 During the sound pressure level and sound absorption
measurements in the receiving room the average temperature
NOTE 5—The mean curvature radius for each hammer face may be
shall be in the range 22 6 5°C and the average relative
determined using a spherometer or other means.
humidity shall be at least 30 %.
8.1.7 The time between successive impacts shall be 100 6
6.6 During the sound pressure level and the corresponding
20 ms.
sound absorption measurements, variations in temperature and
8.1.8 Since friction in the hammer guidance system can
humidity in the receiving room shall not exceed 3°C and 3 %
reduce the velocity of the hammer at impact, the tapping
relative humidity respectively. Temperature and humidity shall
machine shall be checked for friction between the hammers
be measured and recorded as often as necessary to ensure
and the guidance system. Any friction found should be elimi-
compliance.
nated or reduced as much as possible.
6.6.1 If a relative humidity of at least 30 % can not be
8.1.9 Following adjustment of the hammer drop in accor-
maintainedinthereceivingroom,usersofthetestmethodshall
dance with the specifications, the tapping machine is ready for
verify by calculation that changes in the 10 log A term (see
use on any floor structure, including those surfaced with soft or
12.4) due to changes in temperature and humidity do not
resilient materials.
exceed 0.5 dB.
NOTE 6—The above requirements are a subset of the ISO 140/6
NOTE 4—Procedures for calculating air absorption are described inTest requirements.
Method C423.
8.2 Tapping Machine Positions—The tapping machine po-
sitions and orientations described in the following must be
7. Test Specimens
used. Fig. 1 illustrates one case.
7.1 The test specimen shall be prepared and described in the
8.2.1 Position 1—The middle hammer of the tapping ma-
test report in accordance with Annex A1 of Test Method E90.
chine shall be coincident with the midpoint of the floor area,
that is, the point of intersection of floor diagonals. In framed
7.2 Size and Mounting—The test specimen shall have a
construction, adjust this point to the centerline of the closest
minimum lateral dimension of 2.4 m.An area of at least 10 m
structural member or other support member, and arrange the
is recommended. The test specimen shall include all of the
tapping machine so that all hammers fall on the joist.
essential constructional elements and surfacing materials nor-
mally found in an actual installation. Some elements may have 8.2.2 Position 2—Same as position 1, except rotate the
to be reduced in size to fit each labo
...

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. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
´1
Designation: E492 − 09 E492 − 09 (Reapproved 2016)
Standard Test Method for
Laboratory Measurement of Impact Sound Transmission
Through Floor-Ceiling Assemblies Using the Tapping
Machine
This standard is issued under the fixed designation E492; 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.
ε NOTE—Editorially corrected 14.1 in April 2016.
INTRODUCTION
This test method is one of several for evaluating the sound insulating properties of building
elements. It is designed to measure the impact sound transmission performance of an isolated
floor-ceiling assembly, in a controlled laboratory environment. Others in the set deal with field
measurement of impact sound transmission through floor-ceiling assemblies (Test Method E1007),
measurement of sound isolation in buildings (Test Method E336), the measurement of sound
transmission through a common plenum between two rooms (Test Method E1414), and the laboratory
measurement of airborne sound transmission loss of building partitions such as walls, floor-ceiling
assemblies, doors, and other space-dividing elements (Test Method E90).
1. Scope
1.1 This test method covers the laboratory measurement of impact sound transmission of floor-ceiling assemblies using a
standardized tapping machine. It is assumed that the test specimen constitutes the primary sound transmission path into a receiving
room located directly below and that a good approximation to a diffuse sound field exists in this room.
1.2 Measurements may be conducted on floor-ceiling assemblies of all kinds, including those with floating-floor or suspended
ceiling elements, or both, and floor-ceiling assemblies surfaced with any type of floor-surfacing or floor-covering materials.
1.3 This test method prescribes a uniform procedure for reporting laboratory test data, that is, the normalized one-third octave
band sound pressure levels transmitted by the floor-ceiling assembly due to the tapping machine.
1.4 Laboratory Accreditation—The requirements for accrediting a laboratory for performing this test method are given in Annex
A2.
1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.6 This standard does not purport to address 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.
2. Referenced Documents
2.1 ASTM Standards:
C423 Test Method for Sound Absorption and Sound Absorption Coefficients by the Reverberation Room Method
C634 Terminology Relating to Building and Environmental Acoustics
E90 Test Method for Laboratory Measurement of Airborne Sound Transmission Loss of Building Partitions and Elements
E336 Test Method for Measurement of Airborne Sound Attenuation between Rooms in Buildings
This test method is under the jurisdiction of ASTM Committee E33 on Building and Environmental Acoustics and is the direct responsibility of Subcommittee E33.03
on Sound Transmission.
Current edition approved April 1, 2009April 1, 2016. Published May 2009April 2016. Originally approved in 1973. Last previous edition approved in 20042009 as
E492 – 04.E492 – 09. DOI: 10.1520/E0492-09.10.1520/E0492-09R16E01.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
´1
E492 − 09 (2016)
E989 Classification for Determination of Impact Insulation Class (IIC)
E1007 Test Method for Field Measurement of Tapping Machine Impact Sound Transmission Through Floor-Ceiling Assemblies
and Associated Support Structures
E1414 Test Method for Airborne Sound Attenuation Between Rooms Sharing a Common Ceiling Plenum
E2235 Test Method for Determination of Decay Rates for Use in Sound Insulation Test Methods
2.2 ANSI Standards:
S1.10 Pressure Calibration of Laboratory Standard Pressure Microphones
S1.11 Specification for Octave-Band and Fractional-Octave-Band Analog and Digital Filters
S1.43 Specification for Integrating-Averaging Sound-Level Meters
S12.51 Acoustics—Determination of Sound Power Levels of Noise Sources Using Sound Pressure—Precision Methods for
Reverberation Rooms
2.3 ISO Standards:
ISO 140/6 Acoustics—Measurement of Sound Insulation in Buildings and of Building Elements Part 6: Laboratory
Measurements of Impact Sound Insulation of Floors
ISO 3741 Determination of Sound Power Levels of Noise Sources Using Sound Pressure—Precision Methods for Reverberation
Rooms
2.4 IEC Standards:
IEC 60942 Electroacoustics—Sound Calibrators
IEC 61672 Electroacoustics—Sound Level Meters—Part 1: Specifications
3. Terminology
3.1 The following terms used in this test method have specific meanings that are defined in Terminology C634:
airborne sound
average sound pressure level
background noise
decay rate
decibel
diffuse sound field
impact insulation class
one-third octave band
receiving room
reverberant sound field
reverberation room
sound absorption
sound pressure level
3.2 Definitions of Terms Specific to This Standard:
3.2.1 receiving room—a reverberation room below the floor specimen under test in which the sound pressure levels due to the
tapping machine are measured.
4. Summary of Test Method
4.1 A standard tapping machine is placed in operation on a floor specimen that is intended to represent a horizontal separation
between two rooms, one directly above the other. The average spectrum of the sound pressure levels produced by the tapping
machine is measured in the receiving room below in one-third octave bands.
4.2 Since the spectrum depends on the absorption of the receiving room, the sound pressure levels are normalized to a reference
absorption for purposes of comparing results obtained in different receiving rooms that differ in absorption.
5. Significance and Use
5.1 The spectrum of the noise in the room below the test specimen is determined by the following:
5.1.1 The size and the mechanical properties of the floor-ceiling assembly, such as its construction, surface, mounting or edge
restraints, stiffness, or internal damping,
5.1.2 The acoustical response of the room below,
5.1.3 The placement of the object or device producing the impacts, and
5.1.4 The nature of the actual impact itself.
5.2 This test method is based on the use of a standardized tapping machine of the type specified in 8.1 placed in specific
positions on the floor. This machine produces a continuous series of uniform impacts at a uniform rate on a test floor and generates
in the receiving room broadband sound pressure levels that are sufficiently high to make measurements possible beneath most floor
Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http://www.ansi.org.
Available from International Electrotechnical Commission (IEC), 3 rue de Varembé, Case postale 131, CH-1211, Geneva 20, Switzerland, http://www.iec.ch.
´1
E492 − 09 (2016)
types even in the presence of background noise. The tapping machine itself, however, is not designed to simulate any one type of
impact, such as produced by male or female footsteps.
5.3 Because of its portable design, the tapping machine does not simulate the weight of a human walker. Therefore, the
structural sounds, i.e., creaks or booms of a floor assembly caused by such footstep excitation is not reflected in the single number
impact rating derived from test results obtained by this test method. The degree of correlation between the results of tapping
machine tests in the laboratory and the subjective acceptance of floors under typical conditions of domestic impact excitation is
uncertain. The correlation will depend on both the type of floor construction and the nature of the impact excitation in the building.
5.4 In laboratories designed to satisfy the requirements of this test method, the intent is that only significant path for sound
transmission between the rooms is through the test specimen. This is not generally the case in buildings where there are often many
other paths for sounds— flanking sound transmission. Consequently sound ratings obtained using this test method do not relate
directly to sound isolation in buildings; they represent an upper limit to what would be measured in a field test.
5.5 This test method is not intended for field tests. Field tests are performed according to Test Method E1007.
6. Test Rooms
6.1 The test facility shall be so constructed and arranged that the test specimen constitutes the only important transmission path
for the tapping machine sound.
NOTE 1—Common methods for ensuring that this requirement is satisfied include mounting the specimen resiliently in the test opening, mounting the
specimen in a resiliently supported test frame, and supporting rooms resiliently. In general, all rigid connections between the specimen and the test rooms
should be avoided.
6.2 The spatial variations of sound pressure level measured in the receiving room shall be such that the precision requirements
in Annex A1 are satisfied at all frequencies.
6.3 Volume of Receiving Room—The recommended minimum volume of the receiving room is 125 m .
NOTE 2—See Test Method E90 for recommendations for new construction.
6.4 Room Absorption—The sound absorption in the receiving room should be low to achieve the best possible simulation of the
ideal diffuse field condition, and to minimize the region dominated by the direct field of the test specimen. In the frequency range
1/3
that extends from f = 2000/V to 2000 Hz, the absorption in the receiving room (as furnished with diffusers) should be no greater
than:
2/3
A 5 V /3 (1)
where:
V = the room volume, m , and
A = the sound absorption of the room, m .
1/3
6.4.1 For frequencies below f = 2000/V , somewhat higher absorption may be desirable to accommodate requirements of other
test methods (for example, ISO 3741); in any case, the absorption should be no greater than three times the value given by Eq 1.
NOTE 3—For frequencies above 2000 Hz, atmospheric absorption may make it impossible to avoid a slightly higher value than that given in Eq 1.
6.5 During the sound pressure level and sound absorption measurements in the receiving room the average temperature shall
be in the range 22 6 5°C and the average relative humidity shall be at least 30 %.
6.6 During the sound pressure level and the corresponding sound absorption measurements, variations in temperature and
humidity in the receiving room shall not exceed 3°C and 3 % relative humidity respectively. Temperature and humidity shall be
measured and recorded as often as necessary to ensure compliance.
6.6.1 If a relative humidity of at least 30 % can not be maintained in the receiving room, users of the test method shall verify
by calculation that changes in the 10 log A term (see 12.4) due to changes in temperature and humidity do not exceed 0.5 dB.
NOTE 4—Procedures for calculating air absorption are described in Test Method C423.
7. Test Specimens
7.1 The test specimen shall be prepared and described in the test report in accordance with Annex A1 of Test Method E90.
7.2 Size and Mounting—The test specimen shall have a minimum lateral dimension of 2.4 m. An area of at least 10 m is
recommended. The test specimen shall include all of the essential constructional elements and surfacing materials normally found
in an actual installation. Some elements may have to be reduced in size to fit each laboratory’s test opening. The test specimen
shall be sealed to prevent tapping machine operational sounds from entering the room below. The specimen shall be structurally
isolated from the receiving room to avoid significant transmission of vibration from the specimen through the supporting structure
to the room below.
7.3 Floor-surfacing materials, such as vinyl, carpets and pads, especially when installed with adhesive, significantly affect the
response of the test specimen to impacts, both during test and in normal use. Consequently, such materials shall be deemed parts
´1
E492 − 09 (2016)
of the test specimen. The materials and the manner of installing them shall be fully described in the test report. The floor-surfacing
material shall cover the whole test specimen, not merely the portion under the impact machine.
8. Tapping Machine
8.1 This test method is based on the use of a standardized tapping machine that conforms to the following specifications:
8.1.1 The tapping machine shall be motor-driven.
8.1.2 The tapping machine shall have five hammers equally spaced in a line. The distance between centerlines of neighboring
hammers shall be 100 6 3 mm.
8.1.3 Each hammer shall have an effective mass of 500 6 6 g and shall fall freely from a height of 40 6 3 mm.
8.1.4 The falling direction of the hammers shall be perpendicular to the test surface to within 6 0.5°.
8.1.5 The part of the hammer carrying the impact surface shall be cylindrical with a diameter of 30 6 0.2 mm.
8.1.6 The impact surface shall be of hardened steel and shall be approximately spherical with a curvature radius of 500 6 100
mm.
NOTE 5—The mean curvature radius for each hammer face may be determined using a spherometer or other means.
8.1.7 The time between successive impacts shall be 100 6 20 ms.
8.1.8 Since friction in the hammer guidance system can reduce the velocity of the hammer at impact, the tapping machine shall
be checked for friction between the hammers and the guidance system. Any friction found should be eliminated or reduced as much
as possible.
8.1.9 Following adjustment of the hammer drop in accordance with the specifications, the tapping machine is ready for use on
any floor structure, including those surfaced with soft or resilient materials.
NOTE 6—The above requirements are a subset of the ISO 140/6 requirements.
8.2 Tapping Machine Positions—The tapping machine positions and orientations described in the fol
...