ETSI - European Telecommunications Standards Institute
Latest
ETS 300 753-1997
Scope
This European Telecommunication Standard (ETS) specifies acoustic noise emission limits for equipment used in telecommunication locations as specified in the ETS 300 019-1 [3] series. This ETS covers switching@ transmission@ power@ supervisory@ as well as tariff and billing equipment. This ETS also specifies methods for measuring@ reporting and verifying the noise emission of telecommunications equipment. The details of the methods are found in ISO 7779 [1] and ISO 9296 [2]. The descriptor used to quantify acoustic noise emission is the declared A-weighted sound power level in units of bels. The limits contained herein apply only to the airborne acoustic noise generated by equipment during normal operation. That is@ the limits do not apply when operating under emergency conditions or when the equipment is being serviced. Also@ the limits do not apply to equipment features which produce sound as an intentional aspect of their operation@ e.g. alarm signals@ attention signals@ speech signals and so on. (For more information on that topic@ see ETR 116 [5]). Furthermore@ the present document does not specify maximum sound pressure level limits in specific environments. Contained within the present document are 6 annexes. Annex A specifies methods for measuring the acoustic noise emitted from equipment manufactured for open air outdoor locations. Annex B contains tables of recommended A-weighted sound power limits for open air outdoor equipment. Annex C discusses the emission of pure tones from equipment. Annex D reviews the motivation for the creation of this ETS. Annex E discusses the relationship between sound power and sound pressure. Annex F briefly summarizes the sound power measurement methods used within this ETS.