ISO 3740:2019 gives guidance for the use of a set of twelve basic International Standards (see Tables 1, 2 and 3) describing various methods for determining sound power levels from all types of machinery, equipment and products. It provides guidance on the selection of one or more of these standards, appropriate to any particular type of sound source, measurement environment and desired accuracy. The guidance given applies to airborne sound. It is for use in the preparation of noise test codes (see ISO 12001) and also in noise emission testing where no specific noise test code exists. Such standardized noise test codes can recommend the application of particular basic International Standard(s) and give detailed requirements on mounting and operating conditions for a particular family to which the machine under test belongs, in accordance with general principles given in the basic standards.

ISO 3740:2019 is not intended to replace any of the details of, or add any additional requirements to, the individual test methods in the basic International Standards referenced.

NOTE 1 – Two quantities which complement each other can be used to describe the noise emission of machinery, equipment and products. One is the emission sound pressure level at a specified position and the other is the sound power level. The International Standards which describe the basic methods for determining emission sound pressure levels at work stations and at other specified positions are ISO 11200 to ISO 11205 (References [20] to [25]).

NOTE 2 – The sound energy level mentioned in ISO 3741 to ISO 3747 is not addressed in this document as it is not mentioned in any legal requirement. Its application is limited to very special cases of a single burst of sound energy or transient sound defined in ISO 12001.