SN EN ISO 3745 : 2012 AMD 1 2017

Foreword
Introduction
1 Scope
2 Normative references
3 Terms and definitions
4 Measurement uncertainty
5 Test room requirements
   5.1 General
   5.2 Criterion for adequacy of the test room
   5.3 Criterion for background noise
   5.4 Criterion for temperature
   5.5 Humidity correction
6 Instrumentation
   6.1 General
   6.2 Calibration
7 Installation and operation of source under test
   7.1 General
   7.2 Source location
   7.3 Source mounting
   7.4 Auxiliary equipment
   7.5 Operation of source under test
8 Measurement of sound pressure levels for the determination
   of sound power level
   8.1 General
   8.2 Measurement surface
   8.3 Microphone positions
   8.4 Conditions of measurement
   8.5 Data to be obtained
   8.6 Correction for background sound pressure levels
   8.7 Calculation of surface sound pressure level
9 Measurement of single-event sound pressure levels for the
   determination of sound energy level
10 Calculation of sound power level and sound energy level
   10.1 Sound power level
   10.2 Sound energy level
11 Information to be recorded
   11.1 General
   11.2 Sound source under test
   11.3 Acoustic environment
   11.4 Instrumentation
   11.5 Acoustic data
12 Information to be reported
Annex A (normative) General procedures for qualification of
                    anechoic and hemi-anechoic rooms
Annex B (normative) Alternative qualification procedure for
                    anechoic and hemi-anechoic rooms for the
                    determination of sound power levels of
                    specific noise sources
Annex C (normative) Array of microphone positions in a free
                    field
Annex D (normative) Array of microphone positions in a free
                    field over a reflecting plane
Annex E (normative) Coaxial circular paths of microphones in
                    a hemi-free field
Annex F (normative) Meridional paths of microphones in a
                    hemi-free field
Annex G (normative) Spiral paths of microphones in a hemi-free
                    field
Annex H (normative) Calculation of A-weighting sound power level
                    from one-third-octave-band sound power levels
Annex I (normative) Calculation of directivity index and
                    directivity factor
Annex J (informative) Measurement uncertainty
Annex K (informative) Guidelines for the design of test rooms
Bibliography

Provides methods for measuring the sound pressure levels on a measurement surface enveloping a noise source in anechoic and hemi-anechoic rooms, in order to determine the sound power level or sound energy level produced by the noise source. Gives requirements for the test environment and instrumentation, as well as techniques for obtaining the surface sound pressure level from which the sound power level or sound energy level is calculated, leading to results which have a grade 1 accuracy.