GB/T 1859.2-2015Reciprocating internal combustion engines - Measurement of sound power level using sound pressure - Part 2: Survey method (English PDF)

Foreword

GB/T 1859 "Reciprocating internal combustion engines - Measurement of

sound power level using sound pressure" is divided into 4 parts.

- Part 1. Engineering method;

- Part 2. Survey method;

- Part 3. Precision methods for hemi-anechoic rooms;

- Part 4. Survey method using a reference sound source.

This Part is Part 2 of GB/T 1859.

This Part is drafted in accordance with the rules given in GB/T 1.1-2009.

This Part replaces the survey method in GB/T 1859-2000 "Reciprocating

internal combustion engines - Measurement of emitted airborne noise -

Engineering method and survey method".

As compared with GB/T 1859-2000, the main technical changes of this Part are

as follows.

- DELETE relevant content of "engineering method";

- ADD the clause of "Terms and definitions";

- MODIFY the provisions on "Acoustic environment";

- ADD provisions on "Measuring instruments";

- MODIFY and ADD the provisions on "Installation and working conditions";

- MODIFY and ADD the provisions on "Measurement";

- ADD the provisions on "Calculation";

- ADD the clause of "Recording content";

- MODIFY the provisions on "Report";

- DELETE Appendix A and Appendix B in GB/T 1859-2000;

- ADD Appendix A (Normative) "Methods for appraisal of acoustic

environment" and Appendix B "Sound power level of standard reference

conditions".

Introduction

This Part of GB/T 1859 is one of a series of standards for the measurement of

sound power level of reciprocating internal combustion engines using sound

pressure. This series of standards gives a method for measuring the sound

pressure level on the measurement surface enveloping sound source to

calculate the sound power level.

The measurement result of sound power level is basically irrelevant to the test

environment and the installation conditions of sound source. This is an

important reason for the use of sound power level to characterize the noise

radiation of various types of machines and equipment.

The sound power level has the following uses.

- Marking of machine radiation noise under specified conditions;

- Verification of noise marking values;

- Comparison of radiation noise of machines of various models and

dimensions;

- Comparison with the noise limits specified in the purchase contract or

specification;

- Development of engineering measures to reduce machine radiation noise

(Generally, the band sound power level shall also be provided);

- Prediction of noise sound pressure level at specified position.

Table 1 shows the measurement methods of sound power level of three

accuracy classes to which the envelope surface method of this series of

standards applies. The measurement results are accurate to 0.1 dB. The

methods given in this Part allow the determination of A-weighted sound power

level; the accuracy class is Class 3.

Reciprocating internal combustion engines -

Measurement of sound power level using sound

pressure - Part 2. Survey method

1 Scope

This Part of GB/T 1859 specifies the measurement method for sound power

level of reciprocating internal combustion engines - survey method.

This Part is applicable to reciprocating internal combustion engines (unless

otherwise specified, hereafter known as engines for short) in the scope of

application of GB/T 6072.1, and other internal combustion engines to which no

suitable standards apply.

2 Normative references

The following documents are indispensable for the application of this document.

For the dated references, only the versions with the dates indicated are

applicable to this document. For the undated references, the latest version

(including all the amendments) are applicable to this document.

GB/T 3785.1 Electroacoustics - Sound level meters - Part 1. Specifications

GB/T 4129 Acoustics - Requirements for the performance and calibration o

reference sound sources used for determination of sound power levels

GB/T 6072.1 Reciprocating internal combustion engines - Performance -

Part 1. Declarations of power, fuel and lubricating oil consumptions and test

methods - Additional requirements for engines for general use

GB/T 6072.3 Reciprocating internal combustion engines - Performance -

Part 3. Test measurements

GB/T 15173 Electroacoustics - Sound calibrators

3 Terms and definitions

What defined in GB/T 3785.1, GB/T 6072.1 and the following terms and

One or more operating period or operating cycle of the sound source being

measured used to determine the time-averaged sound pressure level, in

seconds (s).

5 Measuring instruments

7 Measurement

9 Recording content

The following content, if applicable, shall be collected and recorded to measure

as required by this Part.

a) Engine.

1) Description of the engine, including model, specifications (e.g., type,

number of strokes, number of cylinders, cylinder bore, stroke, boundary

dimensions, cooling mode; ISO standard power and corresponding

rotational speed, etc.), number, manufacturer;

2) The type of fuel used and its octane or cetane number;

3) Diesel fuel injection timing (static and dynamic) or gasoline engine

ignition timing (static and dynamic);

4) Base characteristics and the way in which the engine is connected to it

(elastic or rigid);

5) The way in which the engine is connected to dynamometer equipment

(elastic or rigid);

6) Installation conditions, including the height of the crankshaft center of

the engine and the bottom of oil pan from the reflecting plane;

7) Description of auxiliary devices, including air filter, exhaust silencer (if

any), cooling fan (if any), and acoustic enclosure (if any);

8) Engine power and corresponding rotational speed during noise

measurements.

b) Acoustic environment.

1) Description of test environment (including physical descriptions of

ground, wall, and ceiling, and sketches of the locations of sound source

being measured and other objects);

2) Description of acoustic environmental appraisal in accordance with the

requirements of Appendix A;

3) Meteorological conditions (including atmospheric pressure,

temperature, relative humidity, and wind speed) near the sound source

during the noise test.

Appendix A

(Normative)

Methods for appraisal of acoustic environment

A.1 General

This appendix specifies the method for measuring environmental correction K2

and can be used to evaluate the effectiveness of a given measurement surface

of the sound source being measured.

The first appraisal test (absolute comparison method, SEE A.2) is performed

using a standard sound source. This method is suitable for indoor or outdoor

use; and is a preferred method for appraisal of test environment, especially

when the frequency band data is required, and the sound source being

measured can be removed from the test site.

The second appraisal test (according to room sound absorption method, SEE

A.3) requires measuring the room sound absorption amount A. This test method

is based on the following premises. The room shape is similar to a cube, is

basically empty; and the room boundary has a sound absorption effect. The

following four methods, reverberation time method, double-surface method,

standard sound source method, and approximation method, can calculate the

room sound absorption amount A. If the sound source being measured cannot

be removed or has a large size, one of the methods may be preferred.

A.2 Absolute comparison method

The standard sound source whose characteristics meet the requirements of

GB/T 4129 is placed on the ground of test environment. The center of the

bottom surface coincides with the center of projection of bottom plane of

reference box on the ground. The measurement surface, microphone position

and its number are the same as those of the sound source being measured.

According to the provisions of Chapter 7, MEASURE the sound power level of

standard sound source, without environmental correction (ASSUME K2=0).

Environmental correction K2 shall be calculated according to the formula (A.1).

Where.

LW* - Test environment sound power level of standard sound source, without

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