NF EN ISO 7779/A1

<p>ISO 7779:2010 specifies procedures for measuring and reporting the noise emission of information technology and telecommunications equipment.</p> <p>The basic emission quantity is the A-weighted sound power level which may be used for comparing equipment of the same type but from different manufacturers, or for comparing different equipment.</p> <p>Three basic noise emission standards for determination of the sound power levels are specified in ISO 7779:2010 in order to avoid undue restriction on existing facilities and experience. ISO 3741 specifies comparison measurements in a reverberation test room; ISO 3744 and ISO 3745 specify measurements in an essentially free field over a reflecting plane. Any one of these three basic noise emission standards can be selected and used exclusively in accordance with ISO 7779:2010 when determining sound power levels of a machine.</p> <p>The A-weighted sound power level is supplemented by the A-weighted emission sound pressure level determined at the operator position(s) or the bystander positions, based on basic noise emission standard ISO 11201. This sound pressure level is not a worker's immission rating level, but it can assist in identifying any potential problems that could cause annoyance, activity interference, or hearing damage to operators and bystanders.</p> <p>Methods for determination of whether the noise emission includes prominent discrete tones or is impulsive in character are specified in annexes.</p> <p>ISO 7779:2010 is suitable for type tests and provides methods for manufacturers and testing laboratories to obtain comparable results.</p> <p>The methods specified in ISO 7779:2010 allow the determination of noise emission levels for a functional unit tested individually.</p> <p>The procedures apply to equipment which emits broadband noise, narrowband noise and noise which contains discrete-frequency components, or impulsive noise.</p> <p>The sound power and emission sound pressure levels obtained can serve noise emission declaration and comparison purposes (see ISO 9296).</p> <p>If sound power levels obtained are determined for a number of functional units of the same production series, they can be used to determine a statistical value for that production series (see ISO 9296).</p>