ISO 4871:1996 pdf download.Acoustics - Declaration and verification of noise emission values of machinery and equipment
1 Scope
This International Standard
— gives information on the declaration of noise emission values,
— describes acoustical and product information to be presented in technical documents for the purposes of noise emission declaration, and
— specifies a method for verifying the noise emission declaration.
It is applicable to machinery and equipment.
The values to be used for the purposes of noise emission declaration are either declared single- number noise emission values, Ld. or declared dual- number noise emission values, L and K. L is a noise emission value determined directly from measurements and K is the uncertainty associated with those measurements. Ld is the sum of L and K and represents an upper limit which values from repeated measurements are unlikely to exceed at a given confidence level; Ld corresponds to the stated or labelled value, L,, defined in ISO 7574-1.
The two forms of noise declaration are alternative means of representing any or all of the A-weighted sound power level, LwA, the A-weighted emission Sound pressure level at specified positions, L,,, and the C-weighted peak emission sound pressure level at specified positions, Lak. The choice as to which of the two forms is used in a particular case depends upon the requirements to be fulfifled. This selection is made, and guidance on the values of K is given, in the appropriate noise test code.
2 Normative references
The following standards contain provisions which, through reference in this text, constitute provisions of this International Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards.
ISO 3740:1980, Acoustics — Determination of sound power levels of noise sources — Guidelines for the use of basic standards and for the preparation of noise test codes.
ISO 3741:—’, Acoustics — Determination of sound power levels of noise sources using sound pressure — Precision methods for reverberation rooms.
ISO 3743-1 1994, Acoustics — Determination of sound power levels of noise sources — Engineering methods for small, movable sources in reverberant fields — Part 1: Comparison method for hard-walled test rooms.
ISO 3743-2:1994, Acoustics — Determination of sound power levels of noise sources using sound pressure — Engineering methods for small, movable sources in reverberant fields — Part 2: Methods for special reverberation test rooms.ISO 4871 pdf download.