1、 AMERICAN NATIONAL STANDARD FOR TELECOMMUNICATIONS ATIS-0600005.2017 Acoustic Measurement ATIS-0600005.2017 ii Foreword The Alliance for Telecommunication Industry Solutions (ATIS) serves the public through improved understanding between providers, customers, and manufacturers. The Sustainability in
2、 Telecom: Energy and Protection (STEP) Committee formerly the Network Interface, Power, and Protection (NIPP) Committee engages industry expertise to develop standards and technical reports for telecommunications equipment and environments in the areas of energy efficiency, environmental impacts, po
3、wer, and protection. The work products of STEP enable vendors, operators, and their customers to deploy and operate reliable, environmentally sustainable, energy efficient communications technologies. STEP is committed to proactive engagement with national, regional, and international standards deve
4、lopment organizations and forums that share its scope of work. The mandatory requirements are designated by the word shall and recommendations by the word should. Where both a mandatory requirement and a recommendation are specified for the same criterion, the recommendation represents a goal curren
5、tly identifiable as having distinct compatibility or performance advantages. The word may denotes an optional capability that could augment the standard. The standard is fully functional without the incorporation of this optional capability. Suggestions for improvement of this document are welcome.
6、They should be sent to the Alliance for Telecommunications Industry Solutions, STEP, 1200 G Street NW, Suite 500, Washington, DC 20005. At the time it approved this document, STEP, which is responsible for the development of this Standard, had the following leadership: E. Gallo, STEP Chair (Ericsson
7、) J. Fuller, STEP Vice Chair (AT however, only the editions cited are applicable for this standard. 1 ETSI 300 753, Equipment Engineering (EE); Acoustic Noise Emitted by Telecommunications Equipment.12 GR-63-CORE, NEBS Requirements: Physical Protection, Issue 2.23 ANSI/ASA S12.10, Acoustics Measurem
8、ent of Airborne Noise Emitted by Information Technology and Telecommunications Equipment.34 ANSI/ASA S12.12, Engineering Method for the Determination of Sound Power Levels of Noise Sources Using Sound Intensity.35 ANSI/ASA S12.54, Acoustics - Determination of Sound Power Levels and Sound Energy Leve
9、ls of Noise Sources Using Sound Pressure - Engineering Method in an Essentially Free Field Over a Reflecting Plane.31This document is available from the European Telecommunications Standards Institute (ETSI). 2This document is available from Telcordia. . 3This document is available from the Acoustic
10、al Society of America (ASA) at . ATIS-0600005.2017 2 6 ATIS-0600336, Design Requirements for Universal Cabinets and Framework.47 ISO/IEC 17025, General Requirements for the Competence of Testing and Calibration Laboratories.58 ASTM E380-92, Standard practice for the use of the international system o
11、f units (SI) (The Modernized Metric System).69 ISO 9296, AcousticDeclared Noise Emission Values of Information Technology and Telecommunications Equipment.53 Definitions The following definitions are taken from ANSI/ASA S12.10 3, ETSI 300 753 1, ANSI/ASA 12.12 4, and ATIS-0600336 6. 3.1 A-weighting
12、filter: Response characteristic of a filter used in acoustic measurement system that attenuates low frequency and high frequency acoustic energy. This filter is used to provide a frequency response characteristic similar to that of the human auditory system. 3.2 Air Moving Devices: Devices that chan
13、ge the velocity and/or direction of air. 3.3 Central office: An environmentally controlled space in which a telecommunications network facility switching system and other associated operating systems are installed. 3.4 Environmentally controlled: A condition of maintaining temperature and humidity w
14、ithin prescribed limits. 3.5 Equipment: A shelf, chassis, or other apparatus that operates to provide a design function either standalone or with other equipment. 3.6 Equipment assembly: A unit of electronic hardware, typically including subassemblies. 3.7 Frame: Synonymous with rack; generally does
15、 not have doors. 3.8 Network telecommunications facility: A dedicated space for housing equipment for receiving, switching, or transmitting telecommunication signals within a network. 3.9 Shelf: An assembly that mounts directly to uprights in a frame without the need for additional structural suppor
16、t. 3.10 Sound intensity: The sound intensity in a specified direction at a point is the average rate of sound energy transmitted in the specified direction through a unit area normal to this direction at the point considered. 3.11 Sound power level: Ten times the logarithm (base 10) of the ratio of
17、a given sound power to the reference sound power. 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: dB. 3.12 Sound pressure level: Twenty times the logarithm (base 10) of the ratio of the root-mean-square soun
18、d pressure to the reference sound pressure. The weighting network (A-weighting) or the width of the frequency band used needs to be indicated. The reference sound pressure is 20 Pa. Units: dBA. 3.13 Subassembly: A set of components designed for a particular use. 4 Acronyms and Abbreviations ANSI Ame
19、rican National Standards Institute 4This document is available from the Alliance for Telecommunications Industry Solutions (ATIS), 1200 G Street N.W., Suite 500, Washington, DC 20005. . 5This document is available from the International Organization for Standardization. 6This document is available f
20、rom the American Society for Testing and Materials (ASTM). . ATIS-0600005.2017 3 ASA Acoustical Society of America ASTM American Society for Testing and Materials ATIS Alliance for Telecommunications Industry Solutions CO Central Office cm centimeter SI International System of Units 5 Measurement Me
21、thodology One of the two measurement methods specified in ANSI/ASA S12.10 3 or the sound intensity method described in ANSI/ASA S12.12 4 shall be used for determining the sound power level for equipment under test. The measurement methods are as follows: Reverberation; Free-field over reflecting pla
22、ne (Engineering or Precision method); and Sound intensity. 6 Units of Measure Units of measure in this standard are shown in both SI and American Standard Units. Where a unit of measure is followed by a value enclosed in parentheses, the second value may be a mathematical approximation of the first
23、value. 7 Equipment Configuration The telecommunications equipment shall be tested in a representative configuration that simulates the maximum expected acoustic noise for the environmental conditions described in this standard. 8 Acoustic Noise Emission Limits The maximum acoustic noise emission lim
24、its for telecommunications equipment to be installed in temperature-controlled environments are specified in Table 8.1. Table 8.1: Maximum Acoustic Noise Emission Limits for Telecommunications Equipment in Temperature-Controlled Environments Environmental Description Sound Power Level, LWAM, dB Temp
25、erature, C* Telecommunication equipment room (unattended/attended) 78 27 Power room 83 27 * Maximum acoustic level that occurs between 23C and 27C should be measured (see methodology, clause 9.1 for clarification). 9 Testing Methodology 9.1 Procedure for Nominal Operating Conditions Sound power meas
26、urements taken between 23C and 27C can be obtained using one of two methods. In the first method, the ambient temperature in the test environment shall be set at the test requirement temperature of 27C ATIS-0600005.2017 4 (consideration for test room temperature variation shall be taken into account
27、 when making measurements). In the second method, the ambient temperature in the test environment shall be 23C 2C, but the air-moving devices within the equipment under test shall be set to the level that the devices would run at when the equipment is operating in an ambient temperature equal to 27C
28、. The recorded acoustic output value shall be the maximum equal to or between 23 and 27C. Cooling device hysteresis shall be taken into account when determining maximum cooling device acoustic level at test temperature (see Annex D for explanation). 9.2 Procedure for Maximum Acoustic Output The ambi
29、ent temperature in the test environment shall be 23C 2C, but the air-moving devices within the equipment under test shall be set to produce the maximum acoustic output level that the devices will produce in an environment from 27C up to and including 55C. The data shall be recorded and the results p
30、rovided in a test report, if required. 10 Retest of Revised Equipment Technical justification shall be documented by the manufacturer to avoid retest. ATIS-0600005.2017 5 Annex A (informative) A Rationale for Sound Power Measurement For many years, the telecommunication industry has been discussing
31、the best way to measure acoustic noise from communications equipment. Both of the methods investigated (source sound power and sound pressure) have advantages and disadvantages. However, in the last decade, the telecommunications industry has worked towards the development of product noise standards
32、 that measure source sound power as an alternative to sound pressure (see GR-63-CORE, Issue 2, Section 4.6 2 where sound power is cited as a future goal). This shift has taken place largely because “sound power test methods are far less susceptible to ambiguities than sound pressure test methods.” 1
33、 The lack of ambiguity that occurs within the measurement of sound power makes it easier and more accurate to measure the noise emission of different systems of devices and gives a better and fairer comparison. While this standard focuses on sound power as the preferred method of measuring the emiss
34、ion of acoustic noise from telecommunications equipment, it is necessary to look at why sound pressure is no longer preferred by the industry. While sound power is the preferred testing method in the industry today, sound pressure testing is not totally discounted; however, sound pressure can be a l
35、ess accurate form of measurement when not performed in a closely controlled and characterized environment. Without properly accounting for the test environment, sound pressure measurements for a given piece of equipment can vary significantly. Additionally, unless a sufficient number of measurement
36、locations is taken, the noise emitted may not be fully captured due to directionality effects. Because it is difficult to consistently measure sound pressure under the testing methodology set by GR-63-CORE 2, this standards committee submits that a sound power method is highly preferable, especially
37、 as it can be used to estimate the sound pressure levels in the installed environment given the sound power of the equipment and information about the room conditions. This standard adopts the sound power method described in ANSI/ASA S12.10 (ISO 7779) 3, that provides complete measuring and reportin
38、g methodologies. This method was adopted by ETSI (European Telecom Standard Institute) in 1997 as a foundation for their sound power testing requirements. Though much of the American telecommunications market currently uses sound pressure measurements it is the decision of this standards body that a
39、 shift to sound power measurement is necessary to harmonize with the international community and to provide the most accurate and repeatable results. ATIS-0600005.2017 6 Annex B (informative) B Explanation of Sound Power Determination Methods B.1 Reverberation Rooms When performing sound power testi
40、ng in a reverberation room, a comparison is made between the acoustic output of a reference sound source and the equipment under test. The requirements for the reverberation room, procedures for room qualification, reference sound source, ambient conditions, test item placement and instrumentation a
41、re given in ANSI/ASA S12.10 3. B.2 Equipment Measurements under Essentially Free Field Conditions over a Reflecting Plane When performing sound power testing under this method, sound pressure level measurements are made at the specified microphone locations around a hypothetical reference surface. T
42、he requirements of the measurement environment, procedures for environment qualification, measurement locations, test item placement, and instrumentation are provided in ANSI/ASA S12.10 3. This standard recommends that the Engineering Method described in ANSI/ASA S12.10 3 (and its associated referen
43、ces) should be used. B.3 Sound Intensity This method provides a procedure for sound power testing that allows more flexibility in the testing environment. The method employs a sound intensity probe that provides a vector quantity representing the acoustic output of the equipment under test. The vect
44、or information can be used to discriminate between the acoustic output of the equipment under test and reflections and background noise. The requirements of the measurement environment, measurement locations, test item placement, and instrumentation are provided in ANSI/ASA S12.12 4. ATIS-0600005.20
45、17 7 Annex C (informative) C Emission Limits The emission limits stated in this standard are derived from issues of perception (such as speech communication and annoyance) rather than hearing loss. Currently, the acoustic output of most telecommunications devices is below the level required to cause
46、 hearing damage. ATIS-0600005.2017 8 Annex D (informative) D Temperature Variation in Test Facility and Cooling Device Hystereses The intent of the requirement is to characterize the noise level of the equipment in a Central Office that may operate to a minimum temperature of 27C. The objective of t
47、he standard is to make the measurement as close as practical to 27C. However, test chambers typically have a temperature tolerance. Attention needs to be taken if fan transitions occur above 27C, but within the test chamber temperature tolerance. Acoustic noise measurements that are taken above 27C that exceed the pass criteria are not considered failures. Hystereses effects can cause cooling devices to maintain higher acoustic output at the target temperature when triggered at a higher temporary temperature.
