AS 1217.2-1985

1 - AS 1217.2-1985 ACOUSTICS - DETERMINATION OF SOUND POWER LEVELS OF NOISE SOURCES - PRECISION METHODS FOR BROAD-BAND SOURCES I
4 - PREFACE
5 - CONTENTS
6 - FOREWORD
7 - SYNOPSIS
8 - SECTION 1. SCOPE AND GENERAL
8 - 1.1 SCOPE.
8 - 1.2 FIELD OF APPLICATION.
8 - 1.2.1 Types of noise.
8 - 1.2.2 Size of source.
8 - 1.3 REFERENCED DOCUMENTS.
8 - 1. 4 MEASUREMENT UNCERTAINTY.
8 - 1.5 DEFINITIONS.
8 - 1.5.1 Reverberation room
8 - 1.5.2 Reverberant sound field
8 - 1.5.3 Mean-square sound pressure
8 - 1.5.4 Sound pressure level
8 - 1.5.5 Sound power level
9 - 1.5.6 Frequency range of interest
9 - 1.5.7 Direct method
9 - 1.5.8 Comparison method
10 - SECTION 2. TEST ROOM REQUIREMENTS
10 - 2.1 GENERAL.
10 - 2.2 ROOM VOLUME.
10 - 2.3 ROOM ABSORPTION.
10 - 2.3.1 General.
10 - 2.3.2 Minimum distance.
10 - 2.3.3 Surface treatment.
10 - 2.4 CRITERION FOR ROOM ADEQUACY.
10 - 2.5 CRITERION FOR BACKGROUND NOISE LEVEL.
10 - 2.6 CRITERIA FOR TEMPERATURE AND HUMIDITY.
11 - SECTION 3. INSTRUMENTATION
11 - 3.1 GENERAL.
11 - 3.2 INDICATING DEVICE.
11 - 3.2.1 General.
11 - 3.2.2 Integration over a fixed time interval.
11 - 3.2.3 Continuous averaging.
11 - 3.3 THE MICROPHONE AND ITS ASSOCIATED CABLE.
11 - 3.4 FREQUENCY RESPONSE OF THE INSTRUMENTATION SYSTEM.
11 - 3.5 FILTER CHARACTERISTICS.
11 - 3.6 CALIBRATION.
12 - SECTION 4. INSTALLATION AND OPERATION OF SOURCE
12 - 4.1 GENERAL.
12 - 4.2 SOURCE POSITION.
12 - 4.3 SOURCE MOUNTING.
12 - 4.4 AUXILIARY EQUIPMENT.
12 - 4. 5 OPERATION OF SOURCE DURING MEASUREMENTS.
13 - SECTION 5. MEASUREMENT OF MEAN-SQUARE SOUND PRESSURE
13 - 5.1 MICROPHONE POSITIONS.
13 - 5.1.1 General.
13 - 5.1.2 Repetition rate.
13 - 5.1.3 Microphone traverse or array.
13 - 5.2 REQUIRED DATA AND CONDITIONS OF MEASUREMENT.
13 - 5.2.1 Sound pressure level readings.
13 - 5.2.2 Period of observation.
13 - 5.2.3 Correction for background sound pressure levels.
13 - 5.2.4 Calculation of mean band pressure levels.
14 - SECTION 6. CALCULATION OF SOUND POWER LEVEL
14 - 6.1 GENERAL.
14 - 6.2 DIRECT METHOD (METHOD I).
14 - 6.2.1 Additional data required.
14 - 6.2.2 Calculation procedure.
14 - 6.3 COMPARISON METHOD (METHOD II).
14 - 6.3.1 General.
14 - 6.3.2 Location of the reference sound source.
14 - 6.3.3 Required additional data.
14 - 6.3.4 Calculation procedure.
15 - SECTION 7. INFORMATION TO BE RECORDED AND REPORTED
15 - 7.1 INFORMATION TO BE RECORDED.
15 - 7.1.1 General.
15 - 7.1.2 Sound source under test.
15 - 7.1.3 Acoustic environment.
15 - 7.1.4 Instrumentation.
15 - 7.1.5 Acoustical data.
15 - 7.2 INFORMATION TO BE REPORTED.
16 - APPENDIX A - TEST ROOM QUALIFICATION PROCEDURE FOR THE MEASUREMENT OF BROAD-BAND SOUND
16 - A1 INTRODUCTION.
16 - A2 INSTRUMENTATION AND EQUIPMENT.
16 - A3 TEST PROCEDURE.
16 - A4 COMPUTATION PROCEDURE.
16 - A5 QUALIFICATION.
17 - APPENDIX B - CHARACTERISTICS AND CALIBRATION OF REFERENCE SOUND SOURCE
17 - B1 CHARACTERISTICS OF REFERENCE SOUND SOURCE.
17 - B2 CALIBRATION OF REFERENCE SOUND SOURCE.
18 - APPENDIX C - COMPUTATIONAL PROCEDURES FOR CALCULATING A- WEIGHTED SOUND POWER LEVEL FROM OCTAVE OR ONE-THIRD OCTAVE BAND POW
19 - APPENDIX D - GUIDELINES FOR THE DESIGN OF REVERBERATION ROOMS
19 - D1 GENERAL.
19 - D2 VOLUME OF TEST ROOM.
19 - D3 SHAPE OF TEST ROOM AND DIFFUSING ELEMENTS.
19 - D4 ABSORPTION OF TEST ROOM.

Sets out a direct method and a comparison method for determining the sound power level produced by a source. Specifies test room requirements, source location and operating conditions, instrumentation and techniques for obtaining an estimate of mean-square sound pressure from which the power sound level of the source in octave or one-third octave bands is calculated. Applies primarily to sources which produce steady broad-band noise.

This standard sets out a direct method and a comparison method for determining the sound power level produced by a source. It specifies test room requirements, source location and operating conditions, instrumentation and techniques for obtaining an estimate of mean-square sound pressure from which the sound power level of the source in octave or one-third octave bands is calculated.FIELD OF