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:
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