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STANDARD
SIST EN 300 753 V1.2.1:2009
ETSI EN 300 753 V1.2.1 (2009-07)European Standard (Telecommunications series) Equipment Engineering (EE);Acoustic noise emitted by telecommunications equipment SIST EN 300 753 V1.2.1:2009
ETSI ETSI EN 300 753 V1.2.1 (2009-07) 2
Reference REN/EE-00009 Keywords acoustic, emission, environment, noise ETSI 650 Route des Lucioles F-06921 Sophia Antipolis Cedex - FRANCE
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© European Telecommunications Standards Institute 2009. All rights reserved.
DECTTM, PLUGTESTSTM, UMTSTM, TIPHONTM, the TIPHON logo and the ETSI logo are Trade Marks of ETSI registered for the benefit of its Members. 3GPPTM is a Trade Mark of ETSI registered for the benefit of its Members and of the 3GPP Organizational Partners. LTE™ is a Trade Mark of ETSI currently being registered for the benefit of its Members and of the 3GPP Organizational Partners. GSM and the GSM logo are Trade Marks registered and owned by the GSM Association. SIST EN 300 753 V1.2.1:2009
ETSI ETSI EN 300 753 V1.2.1 (2009-07) 3 Contents Intellectual Property Rights . 4 Foreword . 4 Introduction . 4 1 Scope . 6 2 References . 6 2.1 Normative references . 6 2.2 Informative references . 7 3 Definitions and symbols . 7 3.1 Definitions . 7 3.2 Symbols . 9 4 Measurement methodology . 9 5 Installation and operation of equipment . 9 5.1 Equipment installation . 9 5.2 Equipment operation "in-use" . 9 5.2.1 Variable emissions - standard temperature test . 9 5.2.2 Variable emissions - high temperature test . 10 6 Acoustic noise emission limits . 10 7 Information to be recorded . 11 8 Information to be reported . 12 9 Verification of declared A-weighted sound power levels . 12 Annex A (normative): Measurement methods for acoustic noise emission from open air outdoor equipment . 13 A.1 Scope . 13 A.2 Source directionality. 13 A.3 Installation and operation of equipment . 13 A.3.1 Daytime simulation . 13 A.3.2 Night-time simulation . 13 A.4 Information to be recorded . 14 A.5 Information to be reported . 14 Annex B (normative): Recommended sound power limits for open air outdoor equipment . 15 Annex C (informative): Recommended method for the detection and reporting of prominent discrete tones . 17 Annex D (informative): Motivation for the present document . 18 Annex E (informative): The relationship between sound power and sound pressure . 19 Annex F (informative): Sound power measurement methods . 20 F.1 Free field over a reflecting plane technique . 20 F.1.1 Concept . 20 F.1.2 Measurement procedure . 20 F.2 Reverberation room technique . 20 F.2.1 Concept . 20 F.2.2 Measurement procedure . 20 F.3 Anechoic and semi-anechoic rooms . 21 F.3.1 Concept . 21 F.3.2 Measurement procedure . 21 History . 22
SIST EN 300 753 V1.2.1:2009
ETSI ETSI EN 300 753 V1.2.1 (2009-07) 4 Intellectual Property Rights IPRs essential or potentially essential to the present document may have been declared to ETSI. The information pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web server (http://webapp.etsi.org/IPR/home.asp). Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web server) which are, or may be, or may become, essential to the present document. Foreword This European Standard (Telecommunications series) has been produced by ETSI Technical Committee Environmental Engineering (EE).
National transposition dates Date of adoption of this EN: 1 July 2009 Date of latest announcement of this EN (doa): 31 October 2009 Date of latest publication of new National Standard or endorsement of this EN (dop/e):
30 April 2010 Date of withdrawal of any conflicting National Standard (dow): 30 April 2010
Introduction Compatibility with the end-use environment is a primary concern for purchasers and manufacturers of telecommunications equipment. An important compatibility issue is the amount of acoustic noise emitted by the equipment. The present document is intended to meet four primary needs of purchasers and manufacturers with regard to this issue:
- specification of acoustic noise emission measurement methods; - specification of acoustic noise emission limits; - specification of a method for reporting acoustic noise emission; - specification of a method for verification of declared noise emission values. To develop practical specifications and to have the capacity to make fair comparisons between equipment, it is essential to have a single, technically established method for the measurement of acoustic emission. Therefore, the present document specifies the use of sound power measurement and, more specifically, adopts ISO 7779 [1] as the primary measurement document.
Sound power levels can be used for direct comparison of noise emission for functionally similar equipment manufactured by different vendors, and/or in the calculation of estimated sound pressure levels for spaces where the equipment is to be installed. The use of sound power level, instead of emission sound pressure level, as the specified quantity for product noise emission has clear precedent within the international noise control community.
The acceptability of the acoustic emission from a piece of equipment depends upon a number of details that vary from installation to installation, and the number of possible installations is extensive. Accordingly, the goal of the present document is to specify limits that are applicable to the major installation categories. SIST EN 300 753 V1.2.1:2009
ETSI ETSI EN 300 753 V1.2.1 (2009-07) 5 The fundamental concern prompting the development of the present document is the potential adverse impact that excessive equipment noise can have on people. For that reason, the impact of noise upon human activities has been carefully considered, and the intent has been to ensure that the acoustic noise emitted is at, or below, generally accepted levels. The perceptual issues considered included task concentration, speech communication, annoyance and other similar parameters. Generally, the relevant noise exposure levels are well below those needed to ensure worker safety and health. Requirements related to worker safety and health (including those related to infrasound and ultrasound) can be found in EC Directive 2003/10/EC [4]. The present document specifies that manufacturers report measured A-weighted sound power values for equipment. Given that it is impractical and unnecessary to measure every manufactured unit, the reported sound power value should be one that all, or nearly all, units of a particular model will not exceed. This means that the reported value needs to take into account both production variation and the precision of the measurement method. ISO 9296 [2] specifies methods that address these issues and is therefore specified in the present document as the method for declaring sound power values. ISO 9296 [2] also specifies a method for verification of declared sound power values. For further information regarding the motivation for the development of the present document, see annex D. SIST EN 300 753 V1.2.1:2009
ETSI ETSI EN 300 753 V1.2.1 (2009-07) 6 1 Scope The present document specifies acoustic noise emission limits for equipment used in telecommunication locations as specified in the EN 300 019-1 [3] series. The present document covers switching, transmission, power, supervisory, as well as tariff and billing equipment.
The present document 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], ISO 9296 [2] and in the basic standards ISO 3741 [7], ISO 3744 [8] and ISO 3745 [9]. 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 the present document. Annex E discusses the relationship between sound power and sound pressure. Annex F briefly summarizes the sound power measurement methods used within the present document. 2 References References are either specific (identified by date of publication and/or edition number or version number) or non-specific. • For a specific reference, subsequent revisions do not apply. • Non-specific reference may be made only to a complete document or a part thereof and only in the following cases:
- if it is accepted that it will be possible to use all future changes of the referenced document for the purposes of the referring document;
- for informative references. Referenced documents which are not found to be publicly available in the expected location might be found at http://docbox.etsi.org/Reference. NOTE: While any hyperlinks included in this clause were valid at the time of publication ETSI cannot guarantee their long term validity. 2.1 Normative references The following referenced documents are indispensable for the application of the present document. For dated references, only the edition cited applies. For non-specific references, the latest edition of the referenced document (including any amendments) applies. [1] ISO 7779: "Acoustics - Measurement of airborne noise emitted by information technology and telecommunications equipment". [2] ISO 9296: "Acoustics - Declared Noise Emission Values of Computer and Business Equipment". [3] ETSI EN 300 019-1 (1994): "Equipment Engineering (EE); Environmental conditions and environmental tests for telecommunications equipment Part 1: Classification of environmental conditions" (this EN has eight sub-parts). SIST EN 300 753 V1.2.1:2009
ETSI ETSI EN 300 753 V1.2.1 (2009-07) 7 [4] EC Directive 2003/10/EC: "On the minimum health and safety requirements regarding the exposure of workers to the risks arising from physical agents (noise)" [OJ L 42, 15.02.2003
p.38-44]. [5] ETSI ETR 116 (1994): "Human Factors (HF); Human factors guidelines for ISDN Terminal equipment design". [6] ECMA TR/27: "Method for prediction of installation noise levels". [7] ISO 3741 (1999): "Acoustics - Determination of sound power levels of noise sources using sound pressure - Precision methods for reverberation rooms". [8] ISO 3744 (1994): "Acoustic - Determination of sound power levels of noise sources using sound pressure - Engineering method in an essentially free field over a reflecting plane". [9] ISO 3745 (2003): "Acoustics - Determination of sound power levels of noise sources using sound pressure - Precision methods for anechoic and hemi-anechoic rooms". 2.2 Informative references The following referenced documents are not essential to the use of the present document but they assist the user with regard to a particular subject area. For non-specific references, the latest version of the referenced document (including any amendments) applies. Not applicable. 3 Definitions and symbols 3.1 Definitions For the purposes of the present document, the following terms and definitions apply: A-weighting filter: response characteristic of a filter used in acoustic measurement systems which attenuates low frequency and high frequency acoustic energy NOTE: This filter is used to provide a frequency response characteristic similar to that of the human auditory system.
business area: area where the principal activity is office / clerical work or similar activities NOTE: These areas typically contain multiple single-person work areas. Sound levels should be low enough to provide good conditions for task concentration and speech communication.
daytime: part of the day considered to extend over normal waking hours NOTE: Typically, the period during which people are most likely to be engaged in activities related to business, education, active recreation, etc. declared A-weighted sound power level (LWAd): statistical maximum A-weighted sound power level for manufactured units, taking into account tolerances of production and measurement variance, described in ISO 9296 [2]
NOTE: Typically, LWAd is 0,3 bels higher than the A-weighted sound power level measured on an average manufactured unit. LWAd is used for all equipment classes and in the specification of noise emission limits. Units: bels. free field over a reflecting plane: sound field in a homogeneous, isotropic medium in the half-space above an infinite, rigid plane surface on which the source is located hemi-anechoic room: room in which a free field over a reflecting plane is obtained SIST EN 300 753 V1.2.1:2009
ETSI ETSI EN 300 753 V1.2.1 (2009-07) 8 high temperature A-weighted sound power level (HLWAd): statistical maximum A-weighted sound power level for manufactured units, taking into account tolerances of production and measurement variance NOTE: The method for determining the high temperature A-weighted sound power level is similar to that used in the determination of declared sound power values, as described in ISO 9296 [2]. HLWAd is used for equipment whose operational noise varies with temperature. Units: bels. high temperature limit: maximum temperature specified for the stated environmental class of the equipment under test according to the relevant subpart of EN 300 019-1 [3] industrial: relating to areas, typically, of transient population and heavy manufacturing activity night-time: part of the day considered to be normal sleeping hours NOTE: This period includes evening and early morning hours when people are likely to be awake but not yet fully involved in typical daytime activities. office: area where individuals are primarily engaged in individual or small group intellectual tasks which require excellent conditions for task concentration and speech communication NOTE: A typical example would be a single-person closed office. power room: area designed to house heavy equipment including, but not limited to, power generation equipment, heating equipment, and ventilation equipment NOTE: Typically occupied only for short periods during servicing. protected area: location intended to be used for rest, recuperation and contemplation NOTE: There is no IEC description for this class but there is a requirement of some European countries for this special category. These areas could be adjacent to hospitals, churches, libraries, etc.
rural: areas, typically, in the countryside with low population density sound power level (LW): logarithm (base 10) of the ratio of a given sound power to the reference sound power NOTE: The weighting network (A-weighting) or the width of the frequency band used needs to be indicated. The reference sound power is 1 pW. Units: bels. sound pressure level (LP): ten times the logarithm (base 10) of the ratio of the time-mean-square sound pressure to the square of the reference sound pressure NOTE: The weighting network (A-weighting) or the width of the frequency band used needs to be indicated. The reference sound pressure is 20 μPa. Units: decibels. telecommunication equipment room: area dedicated to large telecommunication systems NOTE: Unattended rooms are typically occupied only for service and maintenance activities. These activities may last for periods of time greater than one hour. underground vault: sealed underground enclosure which is large enough to be entered for servicing equipment contained therein NOTE: Typically occupied only for service and maintenance activities. These activities may last for periods of time greater than one hour. urban: relating to areas, typically, in towns and cities with high population density SIST EN 300 753 V1.2.1:2009
ETSI ETSI EN 300 753 V1.2.1 (2009-07) 9 3.2 Symbols For the purposes of the present document, the following symbols apply: LW sound power level LWAd declared A-weighted sound power level Lp sound pressure level HLWAd high temperature declared A-weighted sound power level
4 Measurement methodology The measurement methods specified in ISO 7779 [1] and in the basic standards ISO 3741 [7], ISO 3744 [8] and
ISO 3745 [9]. shall be used for determining the sound power of products. Annex A contains additional methods and measurements relating to open air outdoor equipment. 5 Installation and operation of equipment The installation and operation conditions specified in ISO 7779 [1] shall be used for determining the sound power of products. Where there are differences between the present document and ISO 7779 [1], the requirements contained herein shall be followed. The equipment shall be configured and operated according to its normal intended use. Within that constraint and the constraints specified below, the equipment shall be configured and operated to ensure worst case acoustic noise emission.
5.1 Equipment installation The specific installation will depend upon the sound power measurement technique being used (reverberation room or free-field over a reflecting plane), and upon the normal installation requirements of the equipment being measured. 5.2 Equipment operation "in-use" For telecommunication equipment whose operational noise varies with functional load, the electrical input and load conditions of the equipment shall be chosen to obtain full functional utilization of the equipment under test. Dissipation shall be maximized by selection of supply power and load conditions. Only the sound power of continuous, steady-state noise sources shall be measured. Therefore, the equipment is to be operated such that intermittent sources are not active. Such sources include (but are not restricted to) alarms, attention signals, printing mechanisms, disk-drive seeking mechanisms and so on.
For telecommunication equipment whose operational noise varies with temperature (e.g. equipment using variable speed air moving devices), the sound power will be measured with the equipment operating under the two conditions specified in clauses 5.2.1 and 5.2.2. 5.2.1 Variable emissions - standard temperature test For the first test, the ambient temperature in the test environment shall be 23 °C ± 2 °C, in accordance with ISO 7779 [1]. Data obtained from testing as specified in this clause is to be used in the determination of the declared A-weighted sound power level (LWAd) for the equipment. SIST EN 300 753 V1.2.1:2009
ETSI ETSI EN 300 753 V1.2.1 (2009-07) 10 5.2.2 Variable emissions - high temperature test For the second test, the sound power shall be measured with the equipment operating as it would in an ambient temperature equal to the high temperature limit of the reference climatic class (see next paragraph). Data obtained from testing as specified in this clause is to be used in the determination of the high temperature A-weighted sound power level (HLWAd) for the equipment. This requirement can be satisfied using one of the following two methods: • In the first method, the ambient temperature in the test environment shall be the high temperature limit. • In the second method, the ambient temperature in the test environment shall be 23 °C ± 2 °C but, the rotational speed of air moving devices within the equipment under test shall be set to the speed that the devices would run at when the equipment is operating in an ambient temperature equal to the high temperature limit. 6 Acoustic noise emission limits Maximum acoustic noise emission levels for telecommunication equipment are specified in tables 1 to 4. Entries are organized according to the Environmental Classes specified in EN 300 019-1 [3] and to the environmental descriptions found in clause 3.1 of the present document. In accordance with ISO 9296 [2], these maximum product emission levels are declared A-weighted sound power levels, LWAd, in units of bels. As specified in clause 8, manufacturers are to provide declared A-weighted sound power levels for their products. Consequently, the data provided by manufacturers can be compared directly to the values in tables 1 to 4. In order to avoid possible conflict with noise exposure regulations that exist within some European countries, open air outdoor equipment noise emission is not addressed here but is discussed in separate annexes (annexes A and B). The limits apply only to LWAd values, and are not applicable to HLWAd values. Furthermore, the limits apply to the "in-use" operational conditions specified in clause 5.2.
Note that some environmental descriptions have sub-categories based upon typical equipment placement. Equipment intended to be located in close proximity to desk work locations has lower acceptable limits than equipment intended to be located far from desk work locations. These limits apply to a functional unit as defined in clause 4 of ISO 7779 [1]. If a functional unit consists of multiple frames, these limits apply to a single frame as described in clause 5.5 of ISO 7779 [1]. Table 1: Limits for stationary equipment used in weather protected locations
Environmental class Environmental Description LWAd units 3.1 3.2 3.3 Telecommunication equipment room (unattended) bels 7,5 7,5 7,5 Telecommunication equipment room (attended) bels 7,2 7,2 7,2 Business area (> 4 m from desk work locations) bels 6,8 nr nr Business area (< 4 m from desk work locations) bels 6,3 nr nr Office (floor-standing equipment) bels 5,5 nr nr Office (desktop equipment) bels 5,0 nr nr Power room bels 8,3 8,3 8,3
SIST EN 300 753 V1.2.1:2009
ETSI ETSI EN 300 753 V1.2.1 (2009-07) 11 Table 2: Limits for ship environment equipment
Environmental class Environmental Description LWAd units 6.1 Telecommunication equipment room (unattended) bels 7,5 Telecommunication equipment room (attended) bels 7,2 Business area (> 4 m from desk work locations) bels 6,8 Business area (< 4 m from desk work locations) bels 6,3 Office (floor-standing equipment) bels 5,5 Office (desktop equipment) bels 5,0 Power room bels 8,3
Table 3: Limits for portable and non-stationary use equipment
Environmental class Environmental Description LWAd units 7.1 7.2 Telecommunication equipment room (unattended) bels 7,5 7,5 Telecommunication equipment room (attended) bels 7,2 7,2 Bus
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