BS EN ISO 4871:2009

Acoustics. Declaration and verification of noise emission values of machinery and equipment. | Status: Current, Confirmed

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, 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.