JJF 1797-2020 English PDF

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JJF 1797-2020: Calibration Specification for Measuring Instruments for Overall Speech Characteristics of Intercom Systems
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GB/T 3222.2   GB/T 3222.1   JJG 188   JJG 1190   JJF 2012   JJF 1798   

Basic data

Standard ID: JJF 1797-2020 (JJF1797-2020)
Description (Translated English): Calibration Specification for Measuring Instruments for Overall Speech Characteristics of Intercom Systems
Sector / Industry: Metrology & Measurement Industry Standard
Classification of Chinese Standard: A59
Classification of International Standard: 17.140
Word Count Estimation: 20,231
Date of Issue: 2020
Date of Implementation: 2020-04-17
Issuing agency(ies): State Administration for Market Regulation

JJF 1797-2020: Calibration Specification for Measuring Instruments for Overall Speech Characteristics of Intercom Systems

---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.
(Calibration specification for the whole-process voice characteristic measuring instrument of intercom system) National Metrology Technical Specifications of the People's Republic of China Calibration specification for the whole process voice characteristic measuring instrument of the intercom system 2020-01-17 released 2020-04-17 implementation Issued by the State Administration for Market Regulation Voice characteristic measurement of the intercom system Instrument calibration specification Focal point. National Technical Committee of Acoustics Measurement Main drafting unit. Shanghai Institute of Metrology and Testing Technology National Security Alarm System Product Quality Supervision and Inspection Center (Shanghai) China Institute of Metrology Participated in the drafting. Shanghai Jinghui Electronic Equipment Minhang Co., Ltd. East China Branch of China Academy of Information and Communications Technology This specification entrusts the National Acoustics Metrology Technical Committee to be responsible for interpretation The main drafters of this specification. An Zhaoliang (Shanghai Institute of Metrology and Testing Technology) Rong Ling [National Security and Alarm System Product Quality Supervision and Inspection Center (Shanghai)] Zhong Bo (China Institute of Metrology) Participating drafters. Zhou Ziwei (Shanghai Institute of Metrology and Testing Technology) Hu Rong (Shanghai Jinghui Electronic Equipment Minhang Co., Ltd.) Zhao Peng (East China Branch of China Academy of Information and Communications Technology) Chen Wenwang (Shanghai Institute of Metrology and Testing Technology)

table of Contents

Introduction (Ⅱ) 1 scope (1) 2 Reference documents (1) 3 Terms and measurement units (1) 3.1 Full voice features (1) 3.2 Full-range loudness rating (1) 3.3 Mouth reference point (1) 4 Overview (2) 5 Measurement characteristics (2) 5.1 The sound pressure level at the reference point of the simulated mouth at the transmitter (2) 5.2 The deviation of the simulated voice at the sender from the standard voice (2) 5.3 Sound pressure level frequency response at the receiving end (2) 5.4 Sound pressure level linearity at the receiving end (2) 5.5 Frequency response of loudness level at the receiving end (2) 5.6 The receiving end loudness level is linear (3) 6 Calibration conditions (3) 6.1 Environmental conditions (3) 6.2 Measurement standards and other equipment (3) 7 Calibration items and calibration methods (3) 7.1 Calibration items (3) 7.2 Check before calibration (4) 7.3 Sound pressure level at the reference point of the simulated mouth at the transmitter (4) 7.4 The deviation of the simulated voice at the transmitter relative to the standard voice (5) 7.5 Frequency response of sound pressure level at receiving end (5) 7.6 Sound pressure level linearity at the receiving end (6) 7.7 Loudness level frequency response at the receiving end (6) 7.8 Linearity of loudness level at the receiving end (7) 8 Calibration result expression (7) 8.1 Calibration data processing (7) 8.2 Calibration certificate (7) 8.3 Evaluation of Uncertainty of Measurement Results (7) 9 Re-calibration interval (7) Appendix A. Contents and recommended format of calibration certificate (8) Appendix B Evaluation Example of Uncertainty of Measurement Results (12)

Introduction

This specification is compiled in accordance with the requirements and format of JJF 1071-2010 "Rules for the Compilation of National Metrology and Calibration Specifications". This specification mainly refers to GB 31070.1-2014 ``Lou Apartment Intercom System Part 1.General Technical Requirements Requirements", IEC 62820-1-1.2016 "Louyu Intercom System Part 1-1.System Requirements---General Rules" (Buildingintercomsystems-Part 1-1.Systemrequirements-General) The technical requirements for measuring instruments of the fixed value test, and JJG869-2002 "Telephone Electroacoustic Tester", ITU-T P.501 "Test signal for telephone measurement" (Testsignalsforuseintelephonometry). This specification is released for the first time. Calibration specification for the whole process voice characteristic measuring instrument of the intercom system

1 Scope

This specification applies to the frequency range of 100Hz~8kHz, and is used for the whole process of evaluating the sound quality of intercom systems and other products. Tone characteristic measuring instrument calibration.

2 Reference documents

This specification refers to the following documents. JJG175-2015 working standard microphone (electrostatic exciter method) JJG449-2014 Octave and Fractional Octave Filter JJG869-2002 Telephone Electroacoustic Tester JJG1019-2007 working standard microphone (coupling cavity comparison method) JJF 1034-2005 Acoustic measurement terms and definitions JJF 1147-2006 Calibration specification for acoustic characteristics of anechoic room and semi-anechoic room JJF 1580-2016 Calibration Specification for Artificial Mouth GB/T 3102.7 Acoustic quantities and units GB/T 31070.1-2014 Building Intercom System Part 1.General Technical Requirements IEC 62820-1-1.2016 Building Intercom System Part 1-1.System Requirements---General (Building intercomsystems-Part 1-1.Systemrequirements-General) ITU-TP.501 Test signal for telephone measurement (Testsignalsforuseintelephonometry) For dated reference documents, only the dated version applies to this specification; for undated references The latest version (including all amendments) is applicable to this specification.

3 Terms and units of measurement

This specification adopts the quantities and units specified in GB/T 3102.7. The following terms and definitions defined by JJF 1034-2005 are applicable to this specification. 3.1 Overalspeechcharacteristic The quality of the voice signal is maintained during the process of sending, spreading and receiving in the air. 3.2 Overall loudness rating overalloudnessrating OLR The loudness value from the reference point of the transmitting end mouth to the reference point of the receiving end ear. Note. The unit of the overall loudness evaluation value is dB. [GB 31070.1-2014, definition 3.1.6] 3.3 Mouthreferencepoint MRP a) The loudness rating is on the reference axis, 25mm from the point directly in front of the lip plane. ......

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