ANSI S12.31 : 0
Superseded
A superseded Standard is one, which is fully replaced by another Standard, which is a new edition of the same Standard.
A superseded Standard is one, which is fully replaced by another Standard, which is a new edition of the same Standard.
PRECISION METHODS FOR THE DETERMINATION OF SOUND POWER LEVELS OF BROAD-BAND NOISE SOURCES IN REVERBERATION ROOMS
Hardcopy , PDF
12-07-2002
English
INTRODUCTION
1 GENERAL
1.1 Scope and Purpose
1.2 Applicability
1.3 Measurement Uncertainty
2 DEFINITIONS AND SYMBOLS
2.1 Definitions
2.2 Symbols and Recommended Units
3 TEST ROOM REQUIREMENTS
3.1 General
3.2 Room volume
3.3 Room Absorption
3.4 Temperature and Humidity
4 INSTRUMENTATION
4.1 General
4.2 Time Averaging
4.3 The Microphone and Its Associated Cable
4.4 Frequency Response of the Instrumentation
System
4.5 Filter Characteristics
4.6 Calibration
5 INSTALLATION AND OPERATION OF NOISE SOURCE
5.1 General
5.2 Source Location
5.3 Source Mounting
5.4 Auxiliary Equipment
5.5 Operation of Source During Tests
6 DETERMINATION OF AVERAGE SOUND PRESSURE LEVELS
6.1 General
6.2 Microphone Positions
6.3 Required Data and Conditions of Measurement
7 CALCULATION OF SOUND POWER LEVEL
7.1 General
7.2 Direct Method
7.3 Comparison Method
8 TEST ROOM QUALIFICATION PROCEDURE FOR THE MEASUREMENT
OF BROAD-BAND SOUND
8.1 Introduction
8.2 Instrumentation and Equipment
8.3 Test Procedures
8.4 Computation Procedures
8.5 Qualification
9 CHARACTERISTICS AND CALIBRATION OF REFERENCE SOUND
SOURCE
9.1 Characteristics of Reference Sound Source
9.2 Calibration of Reference Sound Source
10 INFORMATION TO BE RECORDED
10.1 Noise Source under Test
10.2 Acoustical Environment
10.3 Instrumentation
10.4 Acoustical Data
11 INFORMATION TO BE REPORTED
12 REFERENCES
12.1 General References
12.2 Text References
12.3 Bibliography
APPENDIX A. GUIDELINES FOR THE DESIGN OF REVERBERATION
ROOMS
A.1 General
A.2 Volume of Test Room
A,3 Shape of Test Room and Diffusing Elements
A.4 Absorption of Test Room Surfaces
APPENDIX B. GUIDELINES FOR THE DESIGN OF ROTATING
DIFFUSERS
APPENDIX C. COMPUTATIONAL PROCEDURES FOR CALCULATING
A-WEIGHTED SOUND POWER LEVEL FROM OCTAVE OR ONE-THIRD
OCTAVE-BAND POWER LEVELS
TABLES:
TABLE 1 Estimated standard deviation of sound power
level determinations for broad-band sources
in reverberation rooms
TABLEII Relative tolerances for the instrumentation
system
TABLE III Corrections for background noise level
TABLE IV Maximum allowable sample standard deviation, s
TABLE V Minimum amount by which narrow-band sound
pressure level must be below the
corresponding octave-band sound pressure level
TABLE VI Calibration accuracy for reference sound
source
TABLE A1 Preferred minimum room volume as a function of
the center frequency for the lowest frequency
band of interest
TABLE A2 Recommended room dimension ratios for
rectilinear rooms
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