GB/T 9911-2018Measurement of airborne noise emitted by marine diesel engine (English PDF)

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).

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 document. 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.