AS 1081.2-1990

1 - AS 1081.2-1990 ACOUSTICS - MEASUREMENTS OF AIRBORNE NOISE EMITTED BY ROTATING ELECTRICAL MACHINERY - SURVEY METHOD
4 - PREFACE
5 - CONTENTS
6 - 0 Introduction
6 - 1 Scope and field of application
6 - 1.1 General
6 - 1.2 Measurement uncertainty
6 - 2 References
7 - 3 Definitions
7 - 3.1 sound pressure level
7 - 3.2 surface sound pressure level
7 - 3.3 sound power level
7 - 3.4 measurement surface
7 - 3.5 reference box
7 - 3.6 measurement distance
7 - 3.7 background noise
7 - 4 Acoustic environment
7 - 4.1 Criteria for adequacy of the test environment
7 - 4.2 Criterion for background noise
7 - 4.3 Wind
7 - 5 Instrumentation
7 - 5.1 General
7 - 5.2 Calibration
8 - 6 Installation and operation of the machine
8 - 6.1 Machine mounting
8 - 6.2 Operation of machine during test
8 - 6.3 Auxiliary equipment and coupled machines
8 - 7 Sound pressure levels on the measurement surface
8 - 7.1 Reference box and measurement surfaces
8 - 7.2 Microphone array
9 - 7.3 Measurement of sound pressure levels
12 - 8 Calculation of surface sound pressure level and sound power level
12 - 8.1 Correction for background noise
12 - 8.2 Calculation of sound pressure level averaged over the measurement surface
12 - 8.3 Calculation of surface sound pressure level and sound power level
12 - 8.4 Calculation of sound power level
14 - 9 Information to be recorded
14 - 9.1 Machine under test
14 - 9.2 Acoustic environment
14 - 9.3 Instrumentation
14 - 9.4 Acoustical data
14 - 10 Information to be reported
15 - Annex A - Qualification procedures for the acoustic environment
15 - A.1 General
15 - A.2 Environmental conditions
15 - A.3 Absolute comparison test to determine K
16 - A.4 Test to determine K using information on the sound absorption area
18 - Annex B - Method for estimating the difference in noise level between no-load and on-load operations
18 - B.1 General
18 - B.2 Installation and operation of machines
18 - B.3 Measurement array
18 - B.4 Measurement of sound pressure levels
19 - B.5 Estimation of differences in level of the noise between no-load and on-load operations
19 - B.6 Information to be recorded
19 - B.7 Information to be reported

Defines survey method for the measurement of noise from electrical machines operating under steady noise conditions, the result of which can be expressed in sound power levels so that all machines tested using This Standard can be directly compared. Identical with and reproduced from ISO 1680-2.

This part of ISO 1680 defines a measurement method for rotating electrical machines operating under steady noise conditions, the result of which can be expressed in sound power levels so that all machines tested using this code can be directly compared. This part of ISO 1680 applies to the measurement of airborne noise from rotating electrical machines, such as motors and generators (d.c. and a.c. machines) of all sizes, when fitted with all auxiliaries which are necessary to achieve the agreed operating conditions (see clause 6). This part of ISO 1680 requires the sound pressure levels to be measured on a rectangular parallelepiped surface enveloping the machines from which the A-weighted sound power level produced by the machine is calculated. It outlines the procedures which shall be used to evaluate the test environment and specifies the characteristics of suitable measuring instruments. This part of ISO 1680 applies to measurements carried out in environmental conditions that meet the criteria given in clause 4 and annex A (environmental correction K 7 dB, correction for background noise 3 dB).

First published in part as AS 1081-1975. Revised and redesignated AS 1081.2-1990.