This Standard also specifies the allowable measurement methods together with the operating conditions and the mounting conditions used for the test.

The emission characteristics include the emission sound pressure levels at specified positions and the sound power level.

The determination of these quantities is necessary for

a) manufacturers of gear units or gearmotors, in order that they may be able to declare the emitted sound,

b) for comparing the sound emitted by gear units and gearmotors under service opera ting, and

c) for the purpose of noise control at the design stage.

This Standard has the aim of ensuring, with its use, the reproducibility of the determination of the airborne sound emission characteristics within specified limits determined by the grade of accuracy of the basic measurement method used.

The sound measurement methods allowed by this Standard are the engineering methods (Grade 2) and the survey methods (Grade 3).

NOTE: The International Standard corresponding to this Standard and the symbol of degree of correspondence are as follows.

ISO 8579-1:2002 Acceptance code for gear units-Part 1: Test code for airborne sound (MOD)

In addition, symbols which denote the degree of correspondence in the contents between the relevant International Standard and JIS are IDT (identical), MOD (modified), and NEQ (not equivalent) according to ISO/ lEC Guide 21-1.

It is applicable to all power transmission gearing other than gears for fine mechanisms.

The methods in this Standard are based on IS0 3744 and IS0 3746.

Note 1 This Standard does not include a method using substitution of a reference sound source in a reverberation room for determining sound power level.

To make use of this method, see IS0 3743.

If it is necessary to determine sound power levels in octave or one-third-octave bands, the procedures of this Standard should be agreed upon between manufacturer and purchaser.