GB/T 6881-2023 English PDFUS$944.00 · In stock
Delivery: <= 5 days. True-PDF full-copy in English will be manually translated and delivered via email. GB/T 6881-2023: Acoustics - Determination of sound power levels and sound energy levels of noise sources using sound pressure - Precision methods for reverberation test rooms Status: Valid GB/T 6881: Historical versions
Basic dataStandard ID: GB/T 6881-2023 (GB/T6881-2023)Description (Translated English): Acoustics - Determination of sound power levels and sound energy levels of noise sources using sound pressure - Precision methods for reverberation test rooms Sector / Industry: National Standard (Recommended) Classification of Chinese Standard: A59 Classification of International Standard: 17.140 Word Count Estimation: 54,573 Date of Issue: 2023-09-07 Date of Implementation: 2024-04-01 Older Standard (superseded by this standard): GB/T 6881.1-2002 Issuing agency(ies): State Administration for Market Regulation, China National Standardization Administration GB/T 6881-2023: Acoustics - Determination of sound power levels and sound energy levels of noise sources using sound pressure - Precision methods for reverberation test rooms---This is a DRAFT version for illustration, not a final translation. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.) will be manually/carefully translated upon your order. ICS 17.140 CCSA59 National Standards of People's Republic of China Replace GB/T 6881.1-2002 Acoustic sound pressure method determines the sound power level and sum of noise sources Sound energy level reverberation chamber precision method (ISO 3741.2010,IDT) Published on 2023-09-07 2024-04-01 Implementation State Administration for Market Regulation Released by the National Standardization Administration Committee Table of contentsPrefaceⅠ Introduction II 1 Scope 1 2 Normative reference documents 1 3 Terms and Definitions 2 4 Standard meteorological conditions 5 5 reverberation chamber 5 6 Instruments and measuring equipment8 7 Definition, location, installation and operation of the noise source to be measured 8 8 Measurements in reverberant rooms 10 9 Determination of sound power level and sound energy level 14 10 Measurement uncertainty20 11 Record content 23 12 Test report 23 Appendix A (informative) Reverberation Room Design Guide 25 Appendix B (informative) Rotating diffuser design guide 27 Appendix C (normative) Reverberation room identification method for broadband sound measurement 28 Appendix D (normative) Reverberation chamber qualification method for discrete frequency component measurements 30 Appendix E (informative) Extension of frequency range to below 100Hz 34 Appendix F (normative) Calculation of octave band sound power level and sound energy level and A weighting using 1/3 octave band sound power level and sound energy level Sound power level and sound energy level36 Appendix G (Informative) Guidelines for the Advancement of Measurement Uncertainty Information 39 Reference 49ForewordThis document complies with the provisions of GB/T 1.1-2020 "Standardization Work Guidelines Part 1.Structure and Drafting Rules of Standardization Documents" Drafting. This document replaces GB/T 6881.1-2002 "Acoustic Sound Pressure Method for Determining the Sound Power Level of Noise Sources Reverberation Chamber Precision Method" and is consistent with Compared with GB/T 6881.1-2002, in addition to structural adjustments and editorial changes, the main technical changes are as follows. ---Added 3.4, 3.14, 3.17, and 3.18 in terms and definitions (see Chapter 3), and deleted "mean square sound pressure" (see the.2002 edition of 3.4); ---Added sound energy level measurement part (see Chapter 9 and Appendix F); ---Added more detailed content on measurement uncertainty (see Chapter 10). This document is equivalent to ISO 3741.2010 "Acoustic Sound Pressure Method for Determination of Sound Power Level and Sound Energy Level of Noise Sources Reverberation Chamber Accuracy" Secret Dharma". Please note that some content in this document may be subject to patents. The publisher of this document assumes no responsibility for identifying patents. This document is proposed by the Chinese Academy of Sciences. This document is under the jurisdiction of the National Acoustic Standardization Technical Committee (SAC/TC17). This document was drafted by. Institute of Acoustics, Chinese Academy of Sciences, Shenzhen Zhongya Mechanical and Electrical Industrial Co., Ltd., Tongji University, Zhejiang Institute of Science and Technology, Zhejiang University, Nanjing University, China Institute of Metrology, Hangzhou Aihua Intelligent Technology Co., Ltd., Highway Science Research Institute of the Ministry of Transport, Beijing Academy of Science and Technology Urban Safety and Environmental Science Institute, China Aircraft Strength Research Institute, Nanjing Changrong Acoustics Co., Ltd. Division, Shanghai Academy of Environmental Sciences, Northwestern Polytechnical University, Shanghai Jiao Tong University, Shanghai Xinhuajing Environmental Protection Engineering Co., Ltd., Changsha Aobang Environmental Protection BAU INDUSTRIAL LIMITED. The main drafters of this document. Cheng Mingkun, Tian Jing, Lv Yadong, Cheng Xiaobin, Li Xiaodong, Yang Jun, Fang Qingchuan, Yu Wuzhou, Mao Dongxing, Zhai Guoqing, Li Zhengguang, Tao Jiancheng, He Longbiao, Xiong Wenbo, Yuan Minxin, Wei Xianwei, Zhang Bin, Li Xianhui, Huang Wenchao, Zhang Rongchu, Zhu Wenying, Chen Ke'an, Jiang Weikang, Wang Bing, Mo Jianyan, Liu Danxiao, Xu Xin. The previous versions of this document and the documents it replaces are as follows. ---First published as GB/T 6881.1-2002 in.2002. ---This is the first revision.IntroductionThis document is one of the standards corresponding to the ISO 3740[3]~ISO 3747[9] series of international standards. This series of standards specifies the determination of Various methods of sound power levels and sound energy levels of machines, equipment and their components. Which method to choose from among a series of standards corresponding to different applications The method depends on the purpose of measuring the sound power level and the facilities available. ISO 3740 [3] provides general guidance for the selection of methods. The ISO 3740[3]~ISO 3747[9] series of standards only give general principles for the operating and installation conditions of machine equipment during measurement. It is necessary for each Establish test specifications for each type of sound source to give detailed requirements for installation, load and operating conditions, and obtain the sound power level under these conditions. or sound energy level. The method given in this document requires that the sound source under test be installed in a reverberant chamber with specific acoustic characteristics. Therefore, the premise of this method is that the measured The sound power or sound energy of a sound source is directly proportional to the mean square sound pressure averaged in time and space, and only depends on the acoustic and geometric characteristics of the room and the space. Physical constants of gas. For sound sources emitting narrowband frequency or discrete frequency sound, precise measurement of the radiated sound power level or sound energy level in the reverberation room requires Does more work than a sound source that emits sound evenly over a wide frequency range. The reasons are. a) The spatio-temporal average sound pressure measured by moving a microphone along a short distance or measured by an array composed of a small number of microphones is not always the average sound pressure of the entire room. A good estimate of the temporal and spatial average sound pressure; b) The normal form of the room and the position of the sound source within the room have a strong influence on the sound power or sound energy radiated by the sound source. For sound sources that emit narrowband sound or discrete modulated sounds, the increased measurement workload includes optimization and performance qualification of the reverberation chamber or the use of more The position of the sound source and the position of the microphone (or increase the length of the moving distance of the microphone). Add low-frequency sound absorbers or install rotating diffusers in the reverberation room body helps reduce measurement workload. The method specified in this document allows the determination of sound power levels and sound energy levels in the 1/3 octave band and from them the calculation of octave band, A-weighted and unweighted total sound power level and sound energy level. The method described in this document meets the level 1 accuracy (precision level) defined in GB/T 19052, and the final sound power level and sound energy level package Corrections are included for possible differences between the meteorological conditions during the test period and the baseline meteorological conditions. For acceptable reverberation loops at lower accuracy For applications in the environment, please refer to ISO 3743-1[4], ISO 3743-2[5], and ISO 3747[9]. Acoustic sound pressure method determines the sound power level and sum of noise sources Sound energy level reverberation chamber precision method1 Scope1.1 Overview This document describes a method for determining the sound power level and sound energy level of a noise source by measuring the sound pressure level in a reverberation chamber. The 1/3 octave band sound power level generated by the noise source (or the sound energy level in the case of burst sound or transient noise) is calculated using the measured sound pressure level Obtained, including corrections for differences between the meteorological conditions during the test at the test site and those corresponding to the reference characteristic impedance. This article The software provides the measurement and calculation process for determining sound power level and sound energy level by direct method and comparative method. Usually, the measurement frequency range includes the 1/3 octave band with a center frequency of 100Hz~10000Hz. Appendix E gives the prescribed method Application Guidelines for Extension to Lower Frequency Ranges. This document cannot be used for the 1/3 octave band frequency range above 10000 Hz. Note. For higher frequencies, the method specified in ISO 9295 can be used. 1.2 Types of noise and noise sources This document applies to various types of noise (steady state, unsteady state, fluctuations, bursts, etc.) defined in GB/T 19052. The sound source under test can be a device, machine, component or accessory. This document is applicable to the measured sound source whose volume is not larger than 2% of the reverberation chamber volume. For sound sources whose volume is greater than 2% of the reverberation chamber volume, the measurement results may not reach the level 1 accuracy specified in GB/T 19052-2003. (Precision level) requirements. Note. Under special circumstances, the sound source volume can be increased to a maximum of 5% of the reverberation chamber volume. For this situation, the relevant noise test specifications give possible test Quantitative uncertainty results. 1.3 Reverberation room The test chamber used for measurements in accordance with this document is a reverberant chamber that meets the specified requirements (see Chapter 5). 1.4 Measurement uncertainty Uncertainty information on A-weighted sound power levels and sound energy levels measured in accordance with this document is given for the specified frequency bands and covering all frequency bands. The uncertainty complies with the level 1 accuracy (precision level) of GB/T 19052-2003.2 Normative reference documentsThe contents of the following documents constitute essential provisions of this document through normative references in the text. Among them, the dated quotations For undated referenced documents, only the version corresponding to that date applies to this document; for undated referenced documents, the latest version (including all amendments) applies to this document. GB/T 3241-2010 Electroacoustic octave and fractional octave filters (IEC 61260.1995, MOD) Note 1.There is no technical difference between the quoted content of GB/T 3241-2010 and the quoted content of IEC 61210.1995. GB/T 3785.1-2010 Electroacoustic sound level meter Part 1.Specification (IEC 61672-1.2002, IDT) GB/T 15173-2010 Electroacoustic sound calibrator (IEC 60942.2003, IDT) GB/T 19052-2003 Guidelines for the drafting and presentation of noise test specifications for noise emitted by acoustic machines and equipment (ISO 12001.1996,IDT) ISO 3382-2 Measurement of acoustic parameters of acoustic rooms Part 2.Reverberation time of ordinary rooms (Acoustics-Measure- ......Tips & Frequently Asked Questions:Question 1: How long will the true-PDF of GB/T 6881-2023_English be delivered?Answer: Upon your order, we will start to translate GB/T 6881-2023_English as soon as possible, and keep you informed of the progress. The lead time is typically 3 ~ 5 working days. The lengthier the document the longer the lead time.Question 2: Can I share the purchased PDF of GB/T 6881-2023_English with my colleagues?Answer: Yes. The purchased PDF of GB/T 6881-2023_English will be deemed to be sold to your employer/organization who actually pays for it, including your colleagues and your employer's intranet.Question 3: Does the price include tax/VAT?Answer: Yes. Our tax invoice, downloaded/delivered in 9 seconds, includes all tax/VAT and complies with 100+ countries' tax regulations (tax exempted in 100+ countries) -- See Avoidance of Double Taxation Agreements (DTAs): List of DTAs signed between Singapore and 100+ countriesQuestion 4: Do you accept my currency other than USD?Answer: Yes. If you need your currency to be printed on the invoice, please write an email to Sales@ChineseStandard.net. In 2 working-hours, we will create a special link for you to pay in any currencies. Otherwise, follow the normal steps: Add to Cart -- Checkout -- Select your currency to pay.Question 5: Should I purchase the latest version GB/T 6881-2023?Answer: Yes. Unless special scenarios such as technical constraints or academic study, you should always prioritize to purchase the latest version GB/T 6881-2023 even if the enforcement date is in future. Complying with the latest version means that, by default, it also complies with all the earlier versions, technically. |
