Detail of JJF 1681-2017

Introduction of JJF 1681-2017

1 Scope The Program is applicable to the pattern evaluation of sound level meters with classification code of 28060500. 2 Normative references The following documents are referenced in the Program. JJG 176-2005 Sound calibrator JJG 482-2005 Verification regulation of laboratory standard microphones (free-field reciprocity method) JJG 790-2005 Verification regulation of laboratory standard microphones (coupler reciprocity method) JJG 1019-2007 Verification regulation of working standard microphones (coupler comparison method) JJF 1001-2011 General terms in metrology and their definitions JJF 1015-2014 General norm for pattern evaluation of measuring instruments JJF 1034-2005 Metrological terms and their definitions for acoustics JJF 1059.1-2012 Evaluation and expression of uncertainty in measurement JJF 1147-2006 Calibration specification for acoustic performance of anechoic rooms and hemi-anechoic rooms JJF 1293-2011 Calibration specification for electrostatic actuators GB/T 3102.7-1993 Quantities and units of acoustics GB/T 3947-1996 Acoustical terminology GB/T 6113.102-2008 Specification for radio disturbance and immunity measuring apparatus and methods - Part 1-2: Radio disturbance and immunity measuring apparatus - Ancillary equipment - Conducted disturbances (CISPR 16-1-2:2006, IDT) GB/T 6113.203-2016 Specification for radio disturbance and immunity measuring apparatus and methods - Part 2-3: Methods of measurement of disturbances and immunity - Radiated disturbance measurements (CISPR 16-2-3:2010, IDT) GB/T 17312 Random-incidence and diffuse-field calibration of sound level meters GB/T 17626.20-2014 Electromagnetic compatibility - Testing and measurement techniques - Emission and immunity testing in transverse electromagnetic (TEM) waveguide ISO 26101:2012 Acoustics - Test methods for the qualification of free-field environments IEC 61000-4-2:2008 Electromagnetic compatibility (EMC) - Part 4-2: Testing and measurement techniques - Electrostatic discharge immunity test IEC 61000-4-3:2010 Electromagnetic compatibility (EMC) - Part 4-3: Testing and measurement techniques-Radiated, radio-frequency, electromagnetic field immunity test IEC 61000-4-6:2008 Electromagnetic compatibility (EMC) - Part 4-6: Testing and measurement techniques - Immunity to conducted disturbances, induced by radio-frequency field IEC 61000-6-2:2005 Electromagnetic compatibility (EMC) - Part 6-2: Generic standards - Immunity for industrial environments IEC 61094-1 Measurement microphones - Part 1: Specifications for laboratory standard microphones IEC 61094-5 Measurement microphones - Part 5: Methods for pressure calibration of working standard microphones by comparison IEC 61094-6 Measurement microphones - Part 6: Eletrostatic actuators for determination of frequency response IEC 61672-1:2013 Electroacoustics - Sound level meters - Part 1: Specifications IEC 61672-2:2013 Electroacoustics - Sound level meters - Part 2: Pattern evaluation tests IEC 62585 Electroacoustics - Methods to determine corrections to obtain the free-field response of a sound level meter CISPR 16-1-1 Specification for radio disturbance and immunity measuring apparatus and methods - Part 1-1: Radio disturbance and immunity measuring apparatus - Measuring apparatus CISPR 16-2-1:2010 (Edition 2.1) Specification for radio disturbance and immunity measuring apparatus and methods - Part 2-1: Methods of measurement of disturbances and immunity - Conducted disturbance measurements CISPR 22:2008 Information technology equipment - Radio disturbance characteristics - Limits and methods of measurement For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. 3 Terms and Definitions For the purposes of this document, the terms and definitions given in JJF 1001-2011, JJF 1034-2005 and GB/T 3947-1996 and the following apply. 3.1 Sound pressure difference between an instantaneous total pressure and the corresponding static pressure Note: Sound pressure is expressed in pascals (Pa). [IEC 61672-1:2013, definition 3.1] 3.2 Sound pressure level ten times the logarithm to the base 10 of the ratio of the time-mean-square of a sound-pressure signal to the square of the reference value Notes: 1. Sound pressure level is expressed in decibels (dB). 2. The reference value is 20µPa. [IEC 61672-1:2013, definition 3.2] 3.3 Frequency weighting difference, as a specified function of frequency, between the level of the frequency-weighted signal indicated on the display device and the corresponding level of a constant-amplitude sinusoidal input signal Note: Level difference is expressed in decibels (dB). [IEC 61672-1:2013, definition 3.3] 3.4 Time weighting exponential function of time, of a specified time constant, that weights the square of a sound-pressure signal [IEC 61672-1:2013, definition 3.4] 3.5 Sound level frequency-weighted sound pressure level level with time weighting or time averaging of the square of a frequency-weighted sound pressure signal Note: Sound level is expressed in decibels (dB). [IEC 61672-1:2013, definition 3.5] 3.6 Time-weighted sound level ten times the logarithm to the base 10 of the ratio of the running time average of the time-weighted square of a frequency-weighted sound-pressure signal to the square of the reference value Notes:

Contents of JJF 1681-2017

Introduction i 1 Scope 2 Normative references 3 Terms and Definitions 3.1 Sound pressure 3.2 Sound pressure level 3.3 Frequency weighting 3.4 Time weighting 3.5 Sound level 3.6 Time-weighted sound level 3.7 Maximum time-weighted sound level 3.8 Peak sound pressure 3.9 Peak sound level 3.10 Time-average sound level 3.11 Sound exposure 3.12 Sound exposure level 3.13 Microphone 3.14 Microphone reference point 3.15 Reference direction 3.16 Sound-incidence angle 3.17 Relative directional response 3.18 Directivity factor 3.19 Directivity index 3.20 Relative frequency-weighted free-field response 3.21 Relative frequency-weighted random-incidence response 3.22 Level range 3.23 Reference sound pressure level 3.24 Reference level range 3.25 Calibration check frequency 3.26 Level linearity deviation 3.27 Linear operating range 3.28 Total range 3.29 Toneburst 3.30 Toneburst response 3.31 Reference orientation 3.32 Coverage probability 3.33 Acceptance limit 4 General 4.1 Principle and application 4.2 Grading and classification 5 Legal management requirements 5.1 Measurement unit 5.2 External structure 5.3 Marking 5.4 Technical data 6 Measurement requirements 6.1 Indication at the calibration check frequency 6.2 Directional response 6.3 Frequency weighting 6.4 Corrections to indicated levels 6.5 Level range 6.6 Under-range indication 6.7 Self-generated noise 6.8 Time weightings F and S 6.9 Toneburst response 6.10 Response to repeated tonebursts 6.11 Overload indication 6.12 C-weighted peak sound level 6.13 Reset 6.14 Analogue or digital output 6.15 Timing function 6.16 Crosstalk 6.17 Power supply 6.18 Radio frequency emissions and disturbances to a public power supply 6.19 Static pressure 6.20 Air temperature 6.21 Relative humidity 6.22 Electrostatic discharge 6.23 a.c. power frequency and radio frequency fields 7 General technical requirements 7.1 Appearance and structure 7.2 Functional requirements 8 Table of pattern evaluation items 9 Number and use method of specimens to be provided 9.1 Number of specimens 9.2 Use method of specimens 10 Test methods and conditions for the test items, data processing and qualification criteria 10.1 General requirements for environmental, electrostatic, and radio-frequency tests 10.2 Influence of static pressure 10.3 Abbreviated test of the combined influence of air temperature and relative humidity 10.4 Influence of air temperature 10.5 Influence of relative humidity 10.6 Influence of electrostatic discharges 10.7 Influence of a.c. power-frequency and radio-frequency fields 10.8 Radio-frequency emissions and public power supply disturbances 10.9 General requirements for electroacoustical performance tests 10.10 Indication at the calibration check frequency 10.11 Directivity 10.12 Tests of frequency weightings with acoustical signals 10.13 Tests of frequency weightings with electrical signals 10.14 Corrections for the effect of reflections from the case of a sound level meter and diffraction around a microphone 10.15 Corrections to obtain free-field or random-incidence sound levels 10.16 Level range 10.17 Under-range indication 10.18 Levels of self-generated noise 10.19 Decay time constants for time weightings F and S 10.20 Toneburst response for sound level meters that measure time-weighted sound level 10.21 Toneburst response for sound level meters that measure sound exposure level or time-averaged sound level 10.22 Response to sequences of repeated tonebursts for sound level meters that measure time-averaged sound level 10.23 Overload indication 10.24 C-weighted peak sound level 10.25 Reset 10.26 Electrical output 10.27 Timing function 10.28 Crosstalk in multi-channel sound level meter systems 10.29 Power supply 11 Measuring instruments and equipment used in the test items 12 Pattern evaluation record Annex A Record format for pattern evaluation of sound level meter Annex B Maximum-permitted uncertainty of measurement