Committees responsible
National foreword
Foreword
Introduction
Method
1 Scope
2 Normative references
3 Definitions
4 Acoustic environment
5 Instrumentation
6 Installation and operation of source under test
7 Measurement of sound pressure levels
8 Calculation of A-weighted surface sound pressure
level and A-weighted sound power level
9 Information to be recorded
10 Information to be reported
Annexes
A (normative) Qualification procedures for the
acoustic environment
B (normative) Microphone array on the hemispherical
measurement surface
C (normative) Microphone array on the parallelepiped
measurement surface
D (informative) Guidelines for the detection of
impulsive noise
E (informative) Bibliography
Tables
0.1 Overview of International Standards for
determination of sound power levels of noise sources
using enveloping surface methods over a reflecting
plane and giving different grades of accuracy
1 Estimated upper values of the standard deviations of
reproducibility of A-weighted sound power levels
determined in accordance with this International
Standard
A.1 Approximate values of the mean sound absorption
coefficient alpha
B.1 Coordinates of key microphone positions (4,5,6,10)
and additional microphone positions (14,15,16,20)
B.2 Coordinates of microphone positions (4,5,6,10) for
sources emitting discrete tones
Figures
1 Examples illustrating reference boxes and
characteristic source dimensions d0 with respect to
the origin of the coordinate system Q
A.1 Environmental correction K2A, in decibels
B.1 Microphone array on the hemisphere - key microphone
positions
B.2 Microphone array on the hemisphere
B.3 Plain view of a spherical measurement surface and
microphone positions around a reference box adjacent
to two reflecting planes
C.1 Procedure for fixing the specified microphone
positions where a side of the measurement surface
exceeds 3d
C.2 Example of a measurement surface and microphone
positions for a small machine
C.3 Example of a measurement surface and microphone
positions for a tall machine with a small base area
C.4 Example of a measurement surface and microphone
positions for a long machine
C.5 Example of a measurement surface and microphone
positions for a medium-sized machine
C.6 Example of a measurement surface and microphone
positions for a large machine
C.7 Measurement surface (parallelpiped) with four
microphone positions for floor-standing appliances
placed against a wall
C.8 Measurement surface (parallelpiped) with three
microphone positions for floor-standing appliances
placed against two walls