ASA S12.55 2012
$123.50
ANSI/ASA S12.55-2012 / ISO 3745:2012 (R2019)American National Standard Acoustics – Determination of sound power levels of noise sources using sound pressure – Precision methods for anechoic and hemi-anechoic rooms (a nationally adopted international standard). This standard replaces ANSI S12.35-1990
| Published By | Publication Date | Number of Pages |
| ASA | 2012 | 88 |
None
PDF Catalog
| PDF Pages | PDF Title |
|---|---|
| 15 | 1 Scope 1.1 General 1.2 Types of noise and noise sources 1.3 Test room 1.4 Measurement uncertainty 2 Normative references |
| 16 | 3 Terms and definitions |
| 22 | 4 Reference meteorological conditions 5 Test rooms 5.1 Acoustic criterion for adequacy of the test room |
| 23 | 5.2 Criteria for background noise |
| 24 | 5.3 Criterion for air temperature |
| 26 | 6 Instrumentation 6.1 Instruments for acoustical measurements 6.2 Instruments for meteorological measurements |
| 27 | 7 Definition, location, installation and operation of noise source under test 7.1 General 7.2 Auxiliary equipment 7.3 Noise source location 7.4 Mounting of the noise source |
| 28 | 7.5 Operation of source during test |
| 29 | 8 Measurement surface 8.1 Spherical measurement surface for use in an anechoic room 8.2 Hemispherical measurement surface for use in a hemi-anechoic room |
| 31 | 9 Determination of sound power levels and sound energy levels 9.1 Measurements in the test room 9.2 Measurement of meteorological conditions 9.3 Microphone positions |
| 37 | 9.4 Determination of sound power levels of a noise source which emits steady or non-steady noise19 9.5 Determination of sound energy levels for a noise source which emits impulsive noise |
| 40 | 9.6 Calculation of directivity indices 9.7 Calculation of surface sound pressure level non-uniformity index |
| 41 | 9.8 Frequency-weighted sound power level and sound energy level 10 Measurement uncertainty 10.1 Methodology |
| 42 | 10.2 Determination of .omc 10.3 Determination of .R0 |
| 43 | 10.4 Typical upper bound values of .R0 |
| 44 | 10.5 Total standard deviation, .tot, and expanded measurement uncertainty, U |
| 45 | 11 Information to be recorded 11.1 General ii © 2012 Acoustical Society of America—All rights reserved. 11.2 Noise source under test 11.3 Test room 11.4 Instrumentation |
| 46 | 11.5 Acoustical data 12 Test report |
| 47 | Annex A (normative) General procedures for qualification of anechoic and hemi-anechoic rooms A.1 General A.2 Instrumentation and measuring equipment |
| 50 | A.3 Installation of test sources and microphones |
| 51 | A.4 Test procedures |
| 53 | A.5 Qualification procedure |
| 55 | Annex B (normative) Qualification procedure for spaces within test rooms used in the determination of sound power levels and sound energy levels of specific noise sources B.1 General B.2 Properties of reflecting plane |
| 56 | B.3 Procedure using two measurement spheres or hemispheres with different radii (two-surface method |
| 57 | Annex C (normative) Calculation of A-weighted sound power levels and A-weighted sound energy levels from one-third-octave band levels C.1 A-weighted sound power levels C.2 A-weighted sound energy levels C.3 Values of j and Cj for use in calculations |
| 59 | Annex D (normative) Array of microphone positions on a spherical measurement surface in a free field |
| 62 | Annex E (normative) Arrays of microphone positions on a hemispherical measurement surface in a hemi-free field |
| 67 | Annex F (normative) Coaxial circular paths of microphones on a hemispherical measurement surface in a hemi-free field |
| 68 | Annex G (normative) Meridional paths of microphones on a hemispherical measurement surface in a hemi-free field |
| 70 | Annex H (normative) Spiral paths of microphones on a hemispherical measurement surface in a hemifree field |
| 71 | Annex I (informative) Guidance on the development of information on measurement uncertainty I.1 General I.2 Considerations on the total standard deviation, .tot I.3 Considerations on .omc |
| 73 | I.4 Considerations on .R0 |
| 80 | I.5 Combined standard uncertainty I.6 Measurement uncertainty based on reproducibility data |
| 81 | I.7 Example of an uncertainty budget for a reference sound source in a national laboratory |
