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GB/T 9911-2018: Measurement of airborne noise emitted by marine diesel engine
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Std ID	Version	USD	Buy	Deliver [PDF] in	Title (Description)
GB/T 9911-2018	English	279	Add to Cart	3 days [Need to translate]	Measurement of airborne noise emitted by marine diesel engine
GB/T 9911-2009	English	559	Add to Cart	3 days [Need to translate]	Measure method of airborne noise emitted by marine diesel engine
GB/T 9911-1988	English	639	Add to Cart	5 days [Need to translate]	Measurement method of airborne noise emitted by marine diesel engine

GB/T 9911-2018: Measurement of airborne noise emitted by marine diesel engine

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Measurement of airborne noise caused by marine diesel engine ICS 47.020.20 U44 National Standards of People's Republic of China Replacing GB/T 9911-2009 Measurement of airborne noise emitted from marine diesel engines Published on.2018-02-06 2018-09-01 Implementation General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China China National Standardization Administration released

Foreword

This standard was drafted in accordance with the rules given in GB/T 1.1-2009. This standard replaces GB/T 9911-2009 "Airborne Noise Measurement Method for Marine Diesel Engines," and GB/T 9911-2009 In contrast, major technological changes include. --- Added the term "sound power level (see 3.1); --- Modify the term "reference body" (see 3.4,.2009 version 3.3); --- Removed the term "measured distance" (see.2009 version 3.5); --- Modified the evaluation method for measurement uncertainty of sound power level (see 4.2, version 4.2 of.2009); --- Modify the engineering method test environment correction limit (see 5.2,.2009 version 5.1.2); --- Increased the test equipment calibration cycle (see 6.2.2). This standard was proposed by China Shipbuilding Industry Corporation. This standard is under the jurisdiction of the National Marine Machinery Standardization Technical Committee (SAC/TC137). This standard is drafted by. China Shipbuilding Industry Corporation Seventh Institute. The main drafters of this standard. Zhu Xiaojian, Xu Beibei, Cui Shiming, Xiao Yinglong, Peng An, and Ji Wen. The previous versions of the standard replaced by this standard are. --- GB 9911-1988, GB/T 9911-2009. Measurement of airborne noise emitted from marine diesel engines

1 Scope

This standard stipulates the imaginary rectangle of the enveloping diesel engine when the marine diesel engine (hereinafter referred to as the diesel engine) operates under the specified steady-state operating conditions. Hexahedron measurement on the surface of the sound pressure level measurement and determination of noise power engineering method and simple method. This standard applies to measurements of airborne noise emitted from diesel engine bench tests.

2 Normative references

The following documents are indispensable for the application of this document. For dated references, only dated versions apply to this article Pieces. For undated references, the latest version (including all amendments) applies to this document. GB/T 3241 Electroacoustic Octave and Fractional Octave Filters GB/T 3785.1 Electroacoustic sound level meter Part 1. Specification GB/T 3947 Acoustic Terms GB/T 4129 Acoustics Performance and calibration requirements for standard sound sources for sound power level determination CB/T 3253 Technical Specifications for Marine Diesel Engines CB/T 3254.2 Bench Test Methods for Marine Diesel Engines

3 Terms and Definitions

The terms and definitions defined in GB/T 3947 and the following apply to this document. 3.1 Sound power level soundpowerlevel LW The base-10 logarithm of the ratio of sound power to reference sound power in decibels (dB). Note. The reference sound power is 1pW. 3.2 Diesel engine airborne noise airbornenoiseemittedbymarinedieselengine Noise emitted from the surface of a diesel engine structure into the air. Note. Including intake noise when equipped with a specified air cleaner or intake muffler. Excludes the diesel engine being tested from the air intake through the external intake pipe The intake noise does not include the exhaust noise and the noise radiated by the gearbox and any driven machinery connected to the diesel engine under test. 3.3 Background noise backgroundnoise The noise generated by a sound source other than the diesel engine under test at the point of measurement on the measurement surface. 3.4 Reference body referencebox The hypothetical minimum rectangular hexahedron enveloping the main sounding component of the diesel engine under test and mounting the gantry and terminating on the reflection plane. 3.5 Measuring surface measurementsurface The hypothetical rectangular hexahedron surface enveloping the reference body and having the measurement point arranged thereon. ...