BSI - BS EN ISO 4871
Acoustics - Declaration and Verification of Noise Emission Values of Machinery and Equipment
|Publication Date:||15 August 1997|
|ICS Code (Noise emitted by machines and equipment):||17.140.20|
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, Lc, 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, LpA, and the C-weighted peak emission sound pressure level at specified positions, LpC,peak. The choice as to which of the two forms is used in a particular case depends upon the requirements to be fulfilled. This selection is made, and guidance on the values of K is given, in the appropriate noise test code.
Guidelines for determining declared noise emission values are given in Annex A.