BS EN ISO 4871:2009

This standard BS EN ISO 4871:2009 Acoustics. Declaration and verification of noise emission values of machinery and equipment is classified in these ICS categories:

• 21.020 Characteristics and design of machines, apparatus, equipment
• 17.140.20 Noise emitted by machines and equipment

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 singlenumber noise emission values, Ld, or declared dualnumber 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, L_wA, the A-weighted emission sound pressure level at specified positions, L_pA, and the C-weighted peak emission sound pressure level at specified positions, L_pC,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 em1ss1on values are given in annex A.