This standard provides the guiding principles for the formulation of noise source sound power and measurement specifications, and briefly describes the precision method, engineering method, quasi-engineering method and simple method for measuring the sound power level of machinery and equipment, as well as a series of national standards, to help users choose the appropriate national standards. There are no modern specific test specifications for special machines, and they should be measured in accordance with certain professional standards. This standard is applicable to the formulation of noise sound power level test specifications for various types of machinery and equipment, and is only applicable to airborne sound and test specifications that require the measurement of noise source sound power levels, but does not include vehicles, ships, aircraft, etc. in motion. GB/T 14367-1993 Basic standards for the determination of sound power levels of acoustic noise sources and criteria for the formulation of noise test specifications GB/T14367-1993 Standard download decompression password: www.bzxz.net
This standard provides the guiding principles for the formulation of noise source sound power and measurement specifications, and briefly describes the precision method, engineering method, quasi-engineering method and simple method for measuring the sound power level of machinery and equipment, as well as a series of national standards, to help users choose the appropriate national standards. There are no modern specific test specifications for special machines, and they should be measured in accordance with certain professional standards. This standard is applicable to the formulation of test specifications for noise sound power levels of various types of machinery and equipment, and is only applicable to airborne sound and test specifications that require the measurement of noise source sound power levels, but does not include moving vehicles, ships, aircraft, etc.

National Standard of the People's Republic of China
Acoustics-Determination of sound power levels af noise sources
Guidelines for the use of basic standards and for the preparation of noise test codesG/T 14367—93
This standard refers to the international standard IS03740-1980 Acoustics-Determination of sound power levels of ... There are no modern specific test specifications for special machines, and they should be measured in accordance with certain professional standards. This standard is applicable to the formulation of test specifications for the sound power level of various types of machines and equipment, and is only applicable to test specifications for airborne sound and noise source sound power level, but does not include vehicles, ships, aircraft, etc. in motion. The sound power level data can be used to:
estimate the sound pressure level generated by the running machine at a known distance in a specified environment; compare the noise radiated by machines of the same model and size; b.
compare the noise radiated by machines of different models and sizes to determine whether the noise radiated by the machine meets the specified upper limit. When designing, determine the required sound transmission loss and the required sound reduction base in certain environments, and provide parameters for the development of low-noise machines and equipment. f
2 Reference standards
GB6881
Determination of sound power level of noise source, reverberation chamber precision method and down-range method GB6882 Determination of sound power level of noise source Anechoic chamber and semi-anechoic chamber precision method GB3767 Determination of sound power level of noise source Industrial method and quasi-engineering method GB3768 Determination of sound power level of noise source Simple method 3 Terms and symbols
3.1 Accuracy
Assessment of experimental results (observation and statistical estimation), general qualitative expression of truth or falsehood. 3.2 The accuracy of the method
depends on the accuracy of its mean value and its precision, expressed by the reproducibility standard deviation, but does not include changes in the noise radiated by the machine itself.
Approved by the National Technical Supervision Bureau on March 17, 1993 and implemented on December 1, 1993
3.3 Reproduction
GB/T14367-93
The degree of consistency of the results obtained for the same noise source under different conditions using the same method. Different conditions refer to the results measured by different operators, different test equipment, in different laboratories and locations, at different or same times. Note: Parameters that indicate the overall dispersion of these results are all prefixed with the word "reproducibility", for example, reproducibility standard deviation, reproducibility square, etc. 3.4 Precision of the method
The consistency between repeated traceability results under specified conditions. 3.5 Standard deviation of laboratory noise (test site) SL, H This standard deviation indicates the dispersion of the average value results measured in m laboratories (test sites) for m noise measurements on the same machine. It is an estimate of the value.
3.6 Repeatability standard deviation S, g
The standard deviation of the results of repeated measurements under the same conditions. That is, the standard deviation of the results measured by the same tester using the same instrument under the same conditions and in the same laboratory (same test site) within a short time interval.
Repeatability standard deviation, composed of a and Gg (see 3.7 and 3. 8). And
S, is an estimated value of,.
3.7 Standard deviation S caused by acoustic measurement conditions. When the radiated noise of the fleet remains constant, this standard deviation is the repeatability standard deviation, which characterizes the random error of the measurement result. 3.8 Standard deviation SBg caused by operating and installation conditions is the standard deviation measured when it is impossible to completely reproduce or maintain the specified operating and installation conditions. This standard deviation is the repeatability standard deviation, which characterizes the dispersion of the radiated noise of the machine. 3. 9 Reproducibility standard deviation SR1 and SF. The standard deviation of the measurement results under reproducible conditions, that is, the standard deviation of the results measured under different conditions (different testers, different instrument equipment and different test locations (laboratories) for the same machine at different times using the same measurement method (under specified operating conditions, but different test conditions are allowed in the basic standard, for example, the arrangement of measuring points). That is,
=V+product=V+product+
When it is very small, the reproducibility standard deviation is expressed as . Se, S are estimated values ​​of R and %.
3.10 Measurement uncertainty
represents the evaluation of the true value of the measured value within a certain range. Note: Measurement uncertainty generally contains multiple components, some of which can be evaluated on the basis of the statistical distribution of the measurement results and can be characterized by experimental standards. Other components can only be evaluated based on experience or other information. 4 National Hao standard 4 applicable to the determination of sound power level .1 Quantity to be measured and determined
Under specified acoustic environmental conditions. Measure the A-weighted or band sound pressure level. From these data, the A-weighted or band sound power level of the sound source can be calculated.
The sound power level should be averaged over time and space. For the basic type of noise, under certain measurement conditions, the fluctuation of the sound power level with space and time should be recorded: 4.2 Some considerations affecting the selection of the full measurement method The applicability of this series of standards is determined by the following items. 9 For laboratory measurements of the size of the noise source expressed as a percentage of the volume of the laboratory;
GB/T14367-93
Noise characteristics of the sound source (continuous load, narrow band, line spectrum, steady state, non-steady state, pulse): d. Relevant frequency range:
Grade of accuracy
f. Required learning data, including sound power level data and other acoustic information (e.g., source index diagram, time waveform). 4.3 The summary of each basic standard can be found in Appendix A.
4.4 The test environment specified in each basic standard can be found in Appendix C.
4.5 The selection procedure
Table 1 gives the application instructions of the four national standards. Table 2 gives the uncertainty of the sound power level determined according to the four documents in this series. The standard deviation obtained by the measurement in accordance with this series of national standards is equal to or less than the value given in Table 2. The standard deviation in Table 2 reflects the cumulative effect of all factors affecting the measurement uncertainty, but does not include the change in sound power level that may occur between one test and another. For example, due to changes in the installation or operating conditions of the sound source, the reproducibility of the test results between laboratories may be better than the uncertainty listed in Table 2 (smaller standard deviation). The level of accuracy is determined according to the purpose of the noise measurement. Several factors that affect the selection of the test method are shown in Table 3. The left side of the table is the basis for selection, and the vertical grid on the right indicates the appropriate test conditions. After determining the test requirements, select the appropriate national standard along the appropriate vertical grid. The diagonal grid indicates that the corresponding national standard is fully suitable for the test item and the uncertainty of the sound power level is within the given range. The hollow vertical grid means that the data obtained is optional. If the sound source can be moved and the test environment meets the requirements of the standard, one of the four standards listed in the table can be selected. If the sound source cannot be moved, only the GB3767 engineering method and the GB 3768 simplified method are available. The selected method depends on the various factors mentioned in Clause 4.2. Appendix B gives information related to method selection. Note: The accuracy of determining the sound power level is expressed in terms of reproducibility standard deviation. They all reflect the cumulative effect of all possible measurement errors.Assuming that the change of sound source power level between multiple tests and the change caused by the change of operation and installation conditions of the measured noise source are not included (0.
The main reason for the error in measuring the sound power level in the anechoic chamber is the complexity of the spatial distribution caused by the directivity of the sound source. In addition to the error caused by the limited number of measuring points (which can be controlled by increasing the number of measuring points), there is also near-field error (for large and medium-sized machines, it may be the main error of anechoic chamber measurement). In a semi-anechoic chamber, spatial irregularities may be enhanced due to the addition of the sound field between the actual sound source and the "image sound source". The sound source located on the reflecting plane Directivity patterns are generally much more complex than those of the same sound source in a free field. Moreover, as the distance from the near field increases, the test radius is usually larger than the radius of the test sphere used in the free field. When measuring sound power levels using different methods, the main causes of errors may not be the same. Although the measurement results of the same accuracy should be comparable within the error range, it can be considered that there are certain non-statistical errors between the results measured by different methods. Therefore, when providing measurement data for the sound power level of a fleet of equipment, the method used must be indicated. National Standard Terminal Number
GB 68886
GB/T14367-93
Various methods for determining the sound power level of machinery and equipment specified in national standards Table 1
Method classification
Test environment
Reverberation room precision
Meet the requirements
Method Village engineering method
Free field engineering
G 376783. 1
Method and quasi-engineering
GB 6882—86
Reverberation room
Outdoor or large
free-field precision anechoic room or semi
GB#7688:3 Simple method
Anechoic room
No need for special
test environment
The volume of the sound source
is less than 1% of the side test roombZxz.net
The maximum size is less than
15㎡
Smaller than the test room
The nature of the noise
The obtainable sound power level
(not Including suspected impulse sound)
Steady state, wide
band, high dispersion or
volume "arbitrary
unrestricted instrument
strengthen the existing test
test environment limits
1/3 times band or
1/1 times band
A weighting and 1/3
octave band or 1/1
A weighting and 1/3
octave band or 1/1
times track
A weighting
optional data
A Weighted sound power level or other weighted sound power as a function of time Directivity data and sound pressure level, other weighted sound power level as a function of time Sound pressure level, other weighted sound power level Table 2 Determination of the uncertainty of measurement of the sound power level (Lw) Expressed in terms of reproducibility Standard deviation (dB) Meters (under standard operating and installation conditions, -0) Octave bandwidth (Hz) National standard No. 1/3 octave bandwidth (Hz) Reverberation chamber GR 6881 Special reverberation chamber Engineering method GR 3767-83 Anechoic chamber GB 6882—83
Semi-anechoic chamber
GB 3768—83
100--160
250--315
400--630
1 000~4 000
800--5 000
A-weighting
630010000
Sound source size
Noise performance
Classification of methods
Suitability of data
Information obtained
Test environment
Loud source·—Stationary
Small sound source·Movable
Steady-state·Broadband
GB/T 14367--93
Table 3 Factors affecting the selection of methods
Symbols in accordance with national standards
Optional symbols are preferred
GB 6881
Steady-state—band…discrete rate
Non-steady-state
Precision method
Engineering method
Engineer method
Simplified method
Sleep noise control work
Type test
Comparison, different models of machines
Same model of machines
Band level
1/3 octave band level
A sound compensation
Other weighting levels
Directional information
Instantaneous type
Reverberation chamber
Special reverberation chamber
Large room, outdoor
Anechoic chamber
On-site, indoor, outdoor
5 Formulation of noise test specifications
5.1 Introduction
GB 376:
G3?6?
When formulating the test specification of the sound power level of special type of machinery and equipment, one of the following methods should be used: a. Precision method (GB6881-66 or GI36882-86); b. Process method (GB 3767--·83); c. Simple method (GB3768-83).
B 6882
GR6882
GB 3768
GB3768
To formulate the noise test specification of special type of machinery and equipment, appropriate standards should be selected from the basic standards listed in Chapter 2 of this standard, and then relevant supplementary instructions should be given. . Operating conditions
b. Placement and installation conditions:
GB/T 14367--93
c. Microphone layout, microphone movement and measurement surface. If the basic standard selected is used to develop the noise test specification, it is clear enough and no additional explanation is required. If the basic standard is used to develop the noise test specification for a special type of machine equipment, the following items should be included: 5.2 Use of basic standards
5.2.1 Under the "Specifications", the test specification shall specify in detail the types of machine equipment to which this test specification is applicable. For "human-type machines with components and accessories", a clear definition of the noise source shall be given, indicating the scope of the sound source to be tested. 5.2.2 The test specification shall indicate the specific data required and explain whether the sound radiation is expressed in terms of weighted sound power or sound power (1/1 octave band or 1/3 octave band of the spectrum).
5.2.3 The "Explanation" shall specifically mention the basic national standard to which this test specification is applied. 5.2.4 The original text of the standard does not have to be used verbatim in the test specification. 5.2.5 Under the terms of "Record Content", the test specification should specify the location of the sound source and the sound transmission in the test room environment, the measurement method and the information on the speed.
5.2.6 All factors related to the installation, placement and operation of the special machinery and equipment included in the standard should be considered. These factors will affect the amount and characteristics of sound radiation. The installation and operating conditions specified in the noise test specification should be obtained. The chapters in the standard that deal with installation and operation conditions are the main chapters of the specification. Note: () Installation conditions: If possible, the equipment under test should be installed in one or more typical locations for normal use. During normal use, if the sound source is placed near the environment (or ceiling), the sound reflection must be affected by these surfaces. Special attention must be paid to simulating this effect in the measurement. In the measurement of reverberation, the sound source should be placed in the place of normal use for ceilings or pond surfaces. For the measurement of quasi-reflection, the sound source should be installed on the reflecting surface. The details should be given.
During the test, auxiliary equipment with equipment operation certificate should not be outside the test environment. ③ Operating conditions, in acoustic measurements, the sound source should be operated under specified conditions. Special types of equipment included in the test specifications should select one or more of the following operating conditions and describe them in detail with specific parameters: Operation at rated load at rated speed:
b. Full load operation (period a is not!
C is not low-pressure <air is sent off,
d is equivalent to operation under normal conditions of high noise radiation e
conventional load operation under detailed provisions. 5.3 Data Preparation
This section of the noise test specification should include detailed instructions to ensure the consistency of the data in the report. The test standard should provide a suitable file format. The format should be suitable for special tests of 1/1 stop band or 1/3 octave band spectrum. The data should include tables or graphs with data. The horizontal coordinate scale of the drawing should be 20mm for each 10dB and 15mm for each filter band. GB/T14367-93
Appendix A
Summary of basic standards for sound power level determination (reference)
A1 GB6881-86 Precision and engineering determination method for reverberation sound sources A1.1 Applicability
Noise control, type testing, comparison of machines and equipment of the same type or different types. A1.2 Test environment
A reverberation room with specified volume and sound absorption characteristics A reverberation room qualified according to the test procedure given in GB6881-86. GB6881-86 gives the design criteria. The relationship between the minimum volume of the reverberation chamber and the lowest reverberation frequency that can be tested, etc. A1.3 Noise source size
The volume of the noise source is preferably less than 1% of the volume of the reverberation chamber. A1.4 Characteristics of the noise radiated by the sound source
Steady-state, broadband, narrowband or discrete source. A1.5 Accuracy
For the precision method, the standard deviation of the sound power level measured at the center frequency of the 500-4000Hz octave band is 1.5dB. For the engineering method, it is 2.0dB, and for the quasi-engineering method, it can be 3.0dB. A7.6 Quantity to be measured
Measure the frequency band sound pressure suffix on the specified path or at a few separate microphone positions. A1.7 Quantity to be determined
Frequency band sound power level and A-weighted sound power level. A1.B Quantities that cannot be obtained
Sound source directional characteristics, instantaneous pattern of radiated noise from non-state noise sources. A2GB6882-86 Precision measurement method for anechoic chamber and semi-anechoic chamber A2.1 Applicability
Noise control, type test, comparison of machines and equipment of the same or different types. A2.2 The test environment
is a free field (full anechoic chamber) or a free field on a reflecting surface (semi-anechoic chamber). In the measurement space where the sound source is located, whether the test environment is suitable shall be checked according to one of the test methods given in Appendix A of the standard. The reflecting surface where the sound source is placed shall be 10% larger than the measuring surface. The sound absorption coefficient of the reflecting surface shall not exceed 0.06. A2.3 Noise source size
The sound source volume should preferably be less than 0.5% of the volume of the anechoic chamber. A2.4 Noise characteristics radiated by the sound source
Various types: for example, steady-state, non-steady-state, broadband, narrowband and discrete frequency. A2.5 Accuracy
Standard deviation of the sound level measurement in the 100DHz octave band: less than or equal to 0.5dB for a fully anechoic room; less than or equal to 1 dB for a semi-anechoic room.
A2.6 Quantity to be measured
Measure the sound pressure level (weighted and frequency band) at the specified microphone measurement position. A2.7 Quantity to be determined
GB/T 14367—93
A-weighted sound power level; frequency band sound power level; directivity of the sound source (optional). A3GB 3767-83 Engineering and quasi-engineering determination methods under free field conditions on a reflecting surface in a large room A3.1 Applicability
Noise control work, type testing, comparison of machines and equipment of the same or different types. A3.2 Test environment
is a white field on a friendly reflective surface (outdoor or indoor or semi-anechoic room. Whether the test environment is suitable should be verified in the measurement space where the sound source is located by one of the test methods given in Appendix A of the standard. The reflective surface of the sound source should be 1% larger than the measurement surface. The sound absorption coefficient of the reflective surface should not exceed 0.06.
A3.3 Sound source size
The maximum linear size is less than 15m.
A3.4 Noise characteristics of sound source radiation
All types. For example, steady state, non-steady state, wide band, narrow band and discrete frequency, A3.5 Accuracy
For engineering level, the standard deviation of the sound power level measured in the 10100 Hz octave band is 1.5dR. For engineering level, the standard deviation of the measured A sound power level is not more than 2 dB. For the quasi-engineering method to measure the A sound power level, the standard deviation is not more than 3 dB. A3.6 Quantity to be measured
Sound pressure at the specified microphone position (weighted or frequency band). A3.7 Quantity to be determined
A-weighted sound power level; frequency band sound power level, A4GB 3768-83 Simple method
A4. 1 Applicability
Comparison of machines or equipment of the same type and general measurement of batches. A4.2 Test environment
Indoor and outdoor installation locations that meet the specified requirements. Whether the test environment is suitable should be checked according to the simple method given in Appendix A of the standard. The reflection plane where the sound source is placed should be higher than the measurement plane, and the sound absorption coefficient of the reflection plane should not exceed 0.1. A4.3 Sound source size
No restrictions.
A4.4 Noise characteristics of sound sources
All types. For example. Steady-state, non-steady-state, wide band, narrow band and discrete frequency. A4.5 Accuracy
For discrete frequency sound sources, the standard deviation of the measured A-weighted sound power level is 5 dB. For radiating steady-state sound sources, the standard deviation is 4 dB.
A4.6 Quantity to be measured
Measure the A-weighted sound level at the specified microphone measurement position. A4.7 Value to be determined
A-weighted sound power level.
B1 Dimensions of noise source
GB/T 1436793
Appendix B
Factors affecting the selection of measurement methods
(References)
Some methods have an upper limit on the volume of the sound source. In the reverberation field, the volume of the sound source is preferably less than 1/5% of the volume of the test room. In the free field, the volume of the sound source is preferably less than 1/5% of the volume of the test room. For the engineering method and the quasi-engineering method (free field method), the maximum size of the sound source should be less than 15 m. In the simple method, there is no limit on the size of the sound source. B2 Available test environment
If the sound source is movable, it can be installed in any test environment, such as an anechoic chamber, a semi-anechoic chamber, outdoors, a reverberation chamber, and a test room with good acoustic performance.
If the sound source is immovable and the measurement is to be carried out under field conditions, in this case, the method described in GB3767-83 or GB3768-83 can be used. The environmental requirements and identification methods are given in the appendices of the above two standards. For machines with a volume greater than 2 m, some semi-anechoic chamber methods can be used, and the methods of GB3767-83 and GB3768-83 are preferably used. On the other hand, for small machines (preferably less than 1m3 in volume) that are movable and radiate mainly steady and audible band noise, any of the national standards in this series may be used. For small machines, the available test environment and the required accuracy determine the choice of method. B3 Noise characteristics
If non-steady-state and impulse noise appear in the source spectrum, any method other than the reverberation field method may be used for measurement, including the measurement of high-scattered frequencies or narrow-band noise. For sound sources with strong radiation directivity or complex directivity patterns, when only the sound power level is required and not the directivity characteristics, the reverberation chamber method is preferred. If the sound source radiates broadband noise, any of the methods specified in this series of national standards may be selected. For example, when measuring noise sources at low frequencies (less than 100Hz), a reverberation chamber with a volume greater than 200m\ is required, while at 10,000Hz, a reverberation chamber with a volume less than 200㎡" can be used. When measuring lower frequencies under field conditions, a larger measurement distance is required. B4 Several levels of accuracy
This series of national standards provides three levels of accuracy for noise power level determination: Level 1 (precision method) GB6881-86 reverberation chamber and GB6882-86 anechoic chamber method. b. Level 2 (engineering method) GB6881-86 special reverberation chamber and GB3767-88 described method. c. Level 3 (simple method) The method described in GB3768-83 Method. Acoustic data required by B5
The data to be obtained depends on the purpose of the noise measurement. The main areas where acoustic data are used are as follows: E5.1 Noise control work
When developing noisy machinery and equipment, quantitative data of 1/1 times or 1/3 times the sound power level are generally required, and sometimes the vibration characteristics of discrete frequency components are also measured. The measurement method most commonly uses level 1 accuracy; level 2 accuracy is also available. B5.2 Type test
For machinery and equipment products, it is generally sufficient to measure their A-weighted sound power level. If you want to obtain more detailed information on noise characteristics from type tests, you need to add some data, such as.Add data on the sound power level of the 1/1 octave band or 1/3 octave band, and the measurement method should have at least Class 2 accuracy.
B5.3 Machine comparison
GB/T14367-93
If it is necessary to compare machines of different types or sizes, in order to make such comparisons meaningful, the data on the sound power of the noise radiated by the machine in the passband, for example, 1/1 octave band or 1/3 octave band, should be measured to Class 2 accuracy. If machines of the same type and specification are to be compared, it is sufficient to measure the A-weighted sound power level. Appendix ℃
Acoustic test environment
(reference)
C1 Environmental conditions provided by the laboratory
Using a laboratory with specified acoustic characteristics, Class 1 accuracy measurements can be obtained, and only machines that are small compared to the laboratory volume can be tested; however, it is expensive to build such an anechoic chamber. A reverberation chamber may save some money. In addition, the type of laboratory used depends on the noise characteristics of the machine to be tested. C1.1 Reverberation chamber
If the radiated noise is steady-state, for relatively small machines (volume less than 1% of the room volume) when a large number of tests are carried out, the volume of the precision test room should be as specified in Table 3 of GB6881-86. Measurements in accordance with this requirement are carried out in the Class 1 method. The volume of the dedicated test room used as the Class 2 method is at least 70m. It is particularly suitable for small machines (volume less than 1% of the room volume) to directly measure the A-weighted sound level.
Reverberation chambers cannot provide directivity data and are not suitable for impulse noise measurements. If the sound source radiation contains significant scattered frequency components, these rooms should be used with caution.
C1.2 Anechoic chambers and anechoic chambers
The anechoic chambers and semi-anechoic chambers described in GB6882-86 are suitable for measuring small sound sources (volume less than 0.5% of the room volume) that radiate different types of sound. This anechoic chamber is also suitable for the measurement of radiated non-steady-state sound or sound sources containing discrete pure tones. The directivity of the sound source can be measured in the anechoic chamber.
Measurement according to the requirements of GB6882-86 belongs to the Class 1 method. C2 Field Test Environment
C2.1 Class 2 Method (Engineering Method and Quasi-Engineering Method) When the sound source is located outdoors or in a large room under free field conditions on a reflecting surface, the measurement methods of engineering and quasi-engineering methods are described in GB3767-83. This method is also suitable for machines and equipment running in ordinary rooms. However, it is necessary to identify whether the acoustic environment is qualified according to the method specified in GB3767-83. C2.2 Class 3 Method (Simplified Method)
When the sound source is located outdoors or in a large room, if there is a condition similar to a free field on a reflecting surface, the simple measurement method of GB3768-83 can be used. This method has no restrictions on the type and size of machines running outdoors. It is also applicable to the measurement of machines in general indoor environments, but the suitability of the acoustic environment must be identified in accordance with the method specified in GB3768--83. Additional notes:
1436793
This standard was reviewed and approved by the National Technical Committee on Acoustics Standardization. This standard was jointly compiled by the Chinese Academy of Computing Sciences, the Institute of Acoustics of the Chinese Academy of Sciences, and the Environmental Protection Institute of the Ministry of Machinery and Electronics Industry. The main drafter of this standard is Yu Bo.
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