GB/T 3785.2-2023 Electroacoustics - Sound level meters - Part 2 : Pattern evaluation tests
1 Scope
This document provides details of the tests necessary to verify conformance to all mandatory specifications given in IEC 61672-1 for time-weighting sound level meters, integrating-averaging sound level meters, and integrating sound level meters. Pattern- evaluation tests apply for each channel of a multi-channel sound level meter, as necessary.
Tests and test methods are applicable to class 1 and class 2 sound level meters. The aim is to ensure that all laboratories use consistent methods to perform pattern-evaluation tests.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 6113.102-2018 Specification for radio disturbance and immunity measuring apparatus and methods - Part 1-2 : Radio disturbance and immunity measuring apparatus - Coupling devices for conducted disturbance measurements (CISPR 16-1-2 :2014, IDT)
Note: There is no technical difference between the contents cited in GB/T 6113.102- 2018 and those cited in CISPR 16-1-2:2006.
GB/T 6113.201-2018 Specification for radio disturbance and immunity measuring apparatus and methods - Part 2-1 : Methods of measurement of disturbances and immunity - Conducted disturbance measurements (CISPR 16-2-1:2014, IDT)
Note: There is no technical difference between the contents cited in GB/T 6113.201-2018 and those cited in CISPR 16-2-1:2010.
GB/T 6113.203-2020 Specification for radio disturbance and immunity measuring apparatus and methods - Part 2-3 : Methods of measurement of disturbances and immunity - Radiated disturbance measurements (CISPR 16-2-3:2016, IDT) .
Note: There is no technical difference between the contents cited in GB/T 6113.203-2020 and those cited in CISPR 16-2- 3:2010.
GB/T 9254.1-2021 Information technology equipment, multimedia equipment and receivers - Electromagnetic compatibility - Part 1 : Emission requirements (CISPR 32:2015, MOD)
Note: There is no technical difference between the contents cited in GB/T 9254.1-2021 and those cited in CISPR 22:2008.
GB/T 17626.2-2018 Electromagnetic compatibility - Testing and measurement techniques - Electrostatic discharge immunity test (IEC 61000-4-2 : 2008, IDT)
GB/T17626.3-2016 Electromagnetic compatibility - Testing and measurement techniques - Radiated, radio-frequency, electromagnetic field immunity test (IEC61000-4-3:2010, IDT)
GB/T 17626.20-2014 Electromagnetic compatibility - Testing and measurement techniques - Emission and immunity testing in transverse electromagnetic (TEM) waveguide (IEC 61000-4-20: 2010, IDT)
ISO/IEC Guide 98-3 Uncertainty of measurement- Part 3: Guide to the expression of uncertainty in measurement (GUM: 1995)
Note: GB/T 27418-2017 Guide to the evaluation and expression of uncertainty in measurement (ISO/IECGuide98-3:2008, MOD)
ISO/IEC Guide 99 International vocabulary of metrology- Basic and general concepts and associated terms (VIM)
Note: JJF 1001-2011 General Terms in Metrology and Their Definitions (ISO/IEC Guide 99 :2007, NEQ)
IEC 60942 Electroacoustics Sound calibrators
Note: GB/T 15173-2010 Electroacoustics - Sound calibrators (IEC 60942:2003.1DT)
IEC 61000-4 6:2008 Electromagnetic compatibility (EMC) - Part 4-6: Testing and measurement techniques Immunity to conducted disturbances, induced by radio frequency field
Note: GB/T 17626.6-2017 Electromagnetic compatibility - Testing and measurement techniques - Immunity to conducted disturbances, induced by radio-frequency fields (IEC 61000-4-6:2013, IDT)
IEC 61000-6-2: 2005 Electromagnetic compatibilty (EMC) - Part 6-2 : Generie standards -Immunity for industrial environments
Note: GB/T 17799.2-2003 Electromagnetic compatibility - Generic standars - Immunity for industrial environments (IEC 61000- 6-2:1999, IDT)
IEC 61094-1 Measurement microphones- Part 1: Specifications for laboratory standard microphones
Note: GB/T 20441.1-2010 Electroacoustics - Measurement microphones - Part 1: Specifications for laboratory standard microphones (IEC 61094.1 : 2000, IDT)
IEC 61094-5 Measurement micro-phones - Part 5: Methods for pressure calibration of working standard microphones by comparison
Note: GB/T 20441.5-2017 Electroacoustics - Measurement microphones - Part 5:Methods for pressure calibration of working standard microphones by comparison (IEC 61094.5:2001, IDT)
IEC61183 Electroacoustics - Random-incidence and diffuse-field calibration of sound level meters
Note: GB/T 17312-1998 Random-incidence and diffuse-field calibration of sound level meters (eqv IEC 61183:1994)
IEC 61672-1 Electroacoustics - Sound level meters - Part 1: Specifications
Note: GB/T 3785.1-2023 Electroacoustics - Sound level meters - Part 1 : Specifications (IEC 61672- 1:2013.IDT)
IEC 62585 Electroacoustics - Methods to determine corrections to obtain the free field response of a sound level meter
Note: GB/T 42553-2023 Electroacoustics - Methods to determine corrections to obtain the free-field response of a sound level meter (IEC 62585:2012, IDT)
CISPR16-1-1 Specification for radio disturbance and immunity measuring apparatus and methods - Part 1-1: Radio disturbance and immunity measuring apparatus - Measuring apparatus
Note: GB/T 6113.101-2021 Specification for radio disturbance and immunity measuring apparatus and methods - Part 1-1 : Radio disturbance and immunity measuring apparatus - Measuring apparatus (CISPR 16-1-1:2019, IDT)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 17626.2-2018, GB/T 17626.3-2016, IEC 61000-4-6: 2008, IEC 61672-1, IEC 62585, Guide 98-3, and ISO/IEC Guide 99 apply.
4 Submission for testing
4.1 At least three specimens of the same pattern of sound level meter shall be submitted for pattern-evaluation testing. As a minimum, the laboratory shall select two of the specimens for testing. At least one of the two specimens shall then be tested fully according to the procedures of this standard. The laboratory shall decide whether the full tests shall also be performed on the second specimen or whether additional limited testing is adequate to approve the pattern.
4.2 An Instruction Manual and all items or accessories that are identified in the Instruction Manual as integral components for the normal mode of operation shall be submitted along with the three sound level meters. Examples of additional items or accessories include a microphone extension device or cable and peripheral equipment.
4.3 If the manufacturer of the sound level meter supplies devices that are to be connected to the sound level meter by cables, then the devices and cables shall be submitted with the sound level meter.
4.4 A calibrated sound calibrator of a model specified in the Instruction Manual for the sound level meter shall be supplied with the sound level meter. An Instruction Manual for the sound calibrator shall also be provided. As required by IEC 61672-1, the model of the calibrator shall conform to the relevant specifications of IEC 60942 for the class of sound calibrator.
5 Marking of the sound level meter and information in the Instruction Manual
5.1 It shall be verified that the sound level meter is marked according to the requirements of IEC 61672-1.
5.2 It shall be verified that the Instruction Manual contains all the information that is required by IEC 61672-1, as relevant to the facilities provided by the sound level meter.
5.3 If the sound level meter does not conform to the requirements of 5.1 and 5.2, no pattern-evaluation tests shall be performed.
5.4 After completion of all tests, the information shall be reviewed to ensure that it is correct and that no applicable acceptance limits are exceeded.
6 Mandatory facilities and general requirements
6.1 No test specified in this document shall be omitted unless the sound level meter does not possess the facility described for the test. When the design of a sound level meter, which has been pattern approved, is changed and a new pattern approval is requested, then, at the discretion of the laboratory, it is not necessary to repeat those tests for electroacoustical performance characteristics that are not affected by the design change.
6.2 A time-weighting sound level meter shall be verified to be able to display A-frequency-weighted, F-time-weighted sound level and to be able to indicate overload and under-range conditions.
6.3 An integrating-averaging sound level meter shall be verified to be able to display A-frequency-weighted, time-averaged sound level and to be able to indicate overload and under-range conditions.
6.4 An integrating sound level meter shall be verified to be able to display A-frequency-weighted sound exposure level and to be able to indicate overload and under-range conditions.
6.5 All display devices for the sound level meter shall be verified to be able to display sound levels or sound exposure levels with the resolution required by IEC 61672-1. The range of the display shall be at least the minimum specified in IEC 61672-1.
6.6 If a sound level meter is capable of measuring maximum or peak sound levels, or both, it shall be verified that a "hold" feature is provided.
6.7 A class 1 sound level meter shall be verified to have frequency-weighting C.
6.8 If the sound level meter is capable of indicating C-weighted peak sound levels, it shall be verified that the capability to display C-weighted, time-weighted sound level or C-weighted, time-averaged sound level is also provided.
6.9 For sound level meters with multiple level ranges, it shall be verified that overlap of the level ranges conforms to the specifications of IEC 61672-1.
6.10 For sound level meters that can display more than one measurement quantity, it shall be verified that there is a means to ascertain the quantity that is being displayed.
6.11 If the sound level meter does not possess the mandatory facilities listed in 6.2 through 6.10, as applicable, the sound level meter does not conform to the specifications of IEC 61672-1 and no pattern-evaluation tests shall be performed.
6.12 For all pattern-evaluation tests, the configuration of the sound level meter, or the multi-channel sound level meter system, shall be as specified in the Instruction Manual for one of the normal modes of operation, including all required accessories. The configuration shall include a windscreen if a windscreen is an integral component for the normal mode of operation, or if the Instruction Manual states that the sound level meter conforms to the specifications of IEC 61672-1 with a windscreen installed around the microphone. The model of the windscreen shall be as stated in the Instruction Manual for use with the sound level meter. All configurations of the sound level meter that are stated in the Instruction Manual as conforming to the requirements of IEC 61672-1 shall be tested.
