Reciprocating internal combustion engine driven alternating current generating sets - Part 10: Measurement of airborne noise by the enveloping surface method
1 Scope
This part defines measurement methods for the determination of airborne noise emitted by reciprocating internal combustion engine driven generating sets in such a way that the total of relevant noise emissions, e.g. exhaust and cooling system noise, together with all other sources of engine noise, are evaluated on a similar basis to yield comparable results. However, when the exhaust and cooling systems are ducted to a remote site, their noise contribution is not to be included in this part.
The essential noise emission characteristic value is the sound power level.
The results of measurement taken in accordance with this part are classified as either accuracy grade 2 or grade 3 depending on which acoustic measurement conditions are complied with. Accuracy grade 2 (i. e., engineering method in accordance with ISO 3744) requires the measuring area to be a substantially acoustic-free field over a reflecting plane (with an environmental correction K2A≤2dB) and with negligible background noise level (background noise correction K1A≤1.3dB). Accuracy grade 3 (i. e. survey method in accordance with ISO 3746) requires the environmental correction K2A to be less or equal than 7dB, and the background noise correction K1A to be less or equal than 3dB.
For the operation of a generating set under steady conditions, this part allows for the calculation of the A-weighted sound power level as well as appropriate octave or one-third octave sound power level for the appropriate accuracy grade.
This part applies to RIC engine driven AC generating sets for fixed and mobile applications with rigid or flexible mountings. It is applicable for land and marine use, excluding generating sets used on aircraft or to propel land vehicles and locomotives.
Note 1: This part has been developed for RIC engine driven AC generating sets, but it can also be applied to RIC engine driven DC generating sets.
Note 2: For some specific applications (e.g. essential hospital supplies, high rise buildings, etc.), supplementary requirements may be necessary. The provisions of this part shall be regarded as a basis.
Note 3: True comparisons can only be made between generating sets when the measurement are classified in the same accuracy grade.
2 Normative references
The following normative documents contain provisions which, through reference in this part of GB/T 2820, constitute provisions of this part. For dated references, subsequent amendments to (excluding correction to), or revisions of, any of these publications do not apply. However, parties to agreements based on this part are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. For undated references, the latest editions apply to this part.
GB/T 2820.1-1997 Reciprocating internal combustion engine driven alternating current generating sets - Part 1: Application, ratings and performance (eqv ISO 8528-1: 1993)
GB/T 2820.2-1997 Reciprocating internal combustion engine driven alternating current generating sets - Part 2: Engines (eqv ISO 8528-2: 1993)
GB/T 6072.1-2000 Reciprocating internal combustion engines - Performance - Part 1: Standard reference conditions, declarations of power, fuel and lubricating oil consumptions, and test methods (idt ISO 3046-1: 1995)
ISO 700:[1 To be published. (Revision of ISO 700: 1982)]1 Arc welding equipment - Welding power sources
ISO 3744: 1994 Acoustics - Determination of sound power levels of noise sources using sound pressure - Engineering method in an essentially free field over a reflecting plane
ISO 3746: 1995 Acoustics - Determination of sound power levels of noise sources using sound pressure - Survey method using an enveloping measurement surface over a reflecting plane
ISO 9614-1: 1993 Acoustics - Determination of sound power levels of noise sources using sound intensity - Part 1: Measurement at discrete points
ISO 9614-2: 1996 Acoustics - Determination of sound power levels of noise sources using sound intensity - Part 2: Measurement by scanning
ISO 11203: 1995 Acoustics - Noise emitted by machinery and equipment - Determination of emission sound pressure levels at a work station and at other specified positions from the sound power level
IEC 60804: 1985 Integrating - Averaging sound level meters
3 Terms and definitions
For the purposes of this part, the following terms and definitions apply:
——for acoustics, those in accordance with ISO 3744 and ISO 3746;
——for the reciprocating internal combustion engine, the terms in accordance with GB/T 6072.1;
——for generating sets, the terms in accordance with GB/T 2820.1~2820.2.
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Symbols
5 Other regulations and requirements
6 Designation of the method
7 Measuring equipment
8 Measuring object
9 Operating conditions of the generating set
10 Measuring surface, measuring distances and measuring points
11 Measuring environment
12 Measurement procedure
13 Determination of the A-weighted sound power level
14 Determination of the emission sound pressure level
15 Accuracy of the procedure and uncertainty of the measurement results
16 Measurement report (measurement record)
17 Summary report
Annex A (Informative) Relation to existing EEC-directives
