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| PDF Pages<\/th>\n | PDF Title<\/th>\n<\/tr>\n | ||||||
|---|---|---|---|---|---|---|---|
| 15<\/td>\n | 1 Scope 1.1 General 1.2 Types of noise and noise sources 1.3 Test room 1.4 Measurement uncertainty 2 Normative references <\/td>\n<\/tr>\n | ||||||
| 16<\/td>\n | 3 Terms and definitions <\/td>\n<\/tr>\n | ||||||
| 22<\/td>\n | 4 Reference meteorological conditions 5 Test rooms 5.1 Acoustic criterion for adequacy of the test room <\/td>\n<\/tr>\n | ||||||
| 23<\/td>\n | 5.2 Criteria for background noise <\/td>\n<\/tr>\n | ||||||
| 24<\/td>\n | 5.3 Criterion for air temperature <\/td>\n<\/tr>\n | ||||||
| 26<\/td>\n | 6 Instrumentation 6.1 Instruments for acoustical measurements 6.2 Instruments for meteorological measurements <\/td>\n<\/tr>\n | ||||||
| 27<\/td>\n | 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 <\/td>\n<\/tr>\n | ||||||
| 28<\/td>\n | 7.5 Operation of source during test <\/td>\n<\/tr>\n | ||||||
| 29<\/td>\n | 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 <\/td>\n<\/tr>\n | ||||||
| 31<\/td>\n | 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 <\/td>\n<\/tr>\n | ||||||
| 37<\/td>\n | 9.4 Determination of sound power levels of a noise source which emits steady or non-steady noise19 \n 9.5 Determination of sound energy levels for a noise source which emits impulsive noise <\/td>\n<\/tr>\n | ||||||
| 40<\/td>\n | 9.6 Calculation of directivity indices 9.7 Calculation of surface sound pressure level non-uniformity index <\/td>\n<\/tr>\n | ||||||
| 41<\/td>\n | 9.8 Frequency-weighted sound power level and sound energy level 10 Measurement uncertainty 10.1 Methodology <\/td>\n<\/tr>\n | ||||||
| 42<\/td>\n | 10.2 Determination of .omc 10.3 Determination of .R0 <\/td>\n<\/tr>\n | ||||||
| 43<\/td>\n | 10.4 Typical upper bound values of .R0 <\/td>\n<\/tr>\n | ||||||
| 44<\/td>\n | 10.5 Total standard deviation, .tot, and expanded measurement uncertainty, U <\/td>\n<\/tr>\n | ||||||
| 45<\/td>\n | 11 Information to be recorded 11.1 General ii \u00a9 2012 Acoustical Society of America\u2014All rights reserved. \n 11.2 Noise source under test 11.3 Test room 11.4 Instrumentation <\/td>\n<\/tr>\n | ||||||
| 46<\/td>\n | 11.5 Acoustical data 12 Test report <\/td>\n<\/tr>\n | ||||||
| 47<\/td>\n | Annex A (normative) General procedures for qualification of anechoic and hemi-anechoic rooms A.1 General A.2 Instrumentation and measuring equipment <\/td>\n<\/tr>\n | ||||||
| 50<\/td>\n | A.3 Installation of test sources and microphones <\/td>\n<\/tr>\n | ||||||
| 51<\/td>\n | A.4 Test procedures <\/td>\n<\/tr>\n | ||||||
| 53<\/td>\n | A.5 Qualification procedure <\/td>\n<\/tr>\n | ||||||
| 55<\/td>\n | Annex B (normative) Qualification procedure for spaces within test rooms used in the determination of \n sound power levels and sound energy levels of specific noise sources B.1 General B.2 Properties of reflecting plane <\/td>\n<\/tr>\n | ||||||
| 56<\/td>\n | B.3 Procedure using two measurement spheres or hemispheres with different radii (two-surface \n method <\/td>\n<\/tr>\n | ||||||
| 57<\/td>\n | Annex C (normative) Calculation of A-weighted sound power levels and A-weighted sound energy levels \n 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 <\/td>\n<\/tr>\n | ||||||
| 59<\/td>\n | Annex D (normative) Array of microphone positions on a spherical measurement surface in a free field <\/td>\n<\/tr>\n | ||||||
| 62<\/td>\n | Annex E (normative) Arrays of microphone positions on a hemispherical measurement surface in a \n hemi-free field <\/td>\n<\/tr>\n | ||||||
| 67<\/td>\n | Annex F (normative) Coaxial circular paths of microphones on a hemispherical measurement surface in \n a hemi-free field <\/td>\n<\/tr>\n | ||||||
| 68<\/td>\n | Annex G (normative) Meridional paths of microphones on a hemispherical measurement surface in a \n hemi-free field <\/td>\n<\/tr>\n | ||||||
| 70<\/td>\n | Annex H (normative) Spiral paths of microphones on a hemispherical measurement surface in a hemifree \n field <\/td>\n<\/tr>\n | ||||||
| 71<\/td>\n | 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 <\/td>\n<\/tr>\n | ||||||
| 73<\/td>\n | I.4 Considerations on .R0 <\/td>\n<\/tr>\n | ||||||
| 80<\/td>\n | I.5 Combined standard uncertainty I.6 Measurement uncertainty based on reproducibility data <\/td>\n<\/tr>\n | ||||||
| 81<\/td>\n | I.7 Example of an uncertainty budget for a reference sound source in a national laboratory <\/td>\n<\/tr>\n<\/table>\n","protected":false},"excerpt":{"rendered":" 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<\/b><\/p>\n |