scope:

This Standard applies to information technology and telecommunications equipment.

This Standard specifies:

- the method of determining the declared noise emission values of a batch of machines,

- acoustical and product information to be given in technical documents supplied to users by the manufacturer,

- the method for verifying the declared noise emission values given by the manufacturers.

The uniform methods in this Standard use the noise emission data obtained in accordance with ANSI/ASA S12.10/Part 1, and the statistical methods and procedures specified in ISO 4871 and the ISO 7574 series.

The primary declared noise emission value is the declared A-weighted sound power level, L_WAd (a statistical maximum value corresponding to L_c in ISO 7574-1). The secondary declared noise emission value is the declared A-weighted emission sound pressure level, L_pAm (a mean value), at the operator or bystander positions.

The declared A-weighted sound power level, L_Wad, permits comparison of noise emissions between different products and permits prediction of installation or work-place noise immission levels.

Although the most useful quantity for calculating immission levels due to one or more sound sources is usually the declared A-weighted sound power level of the individual source(s), the declared A-weighted emission sound pressure level, L_pAm, may be used to estimate the immission level in the immediate vicinity of an isolated piece of equipment.

To avoid confusion between sound power levels and emission sound pressure levels, the A-weighted sound power level is declared in bels and the A-weighted emission sound pressure level is declared in decibels.