This International Standard gives guidance for the use of a series of nine International Standards describing various methods for determining the sound power levels from all types of machinery and equipment. It provides: — brief summaries of these basic International Standards; — guidance on the selection of one or more of these standards which are appropriate to any particular type (see clause 5 and annex D). The guidance given applies only to airborne sound. It is for use in the preparation of noise test codes (see ISO 12001) and also in noise testing where no specific noise test code exists. This International Standard is not intended to replace any of the details of, or add any additional requirements to, the individual test methods in the other basic standards referred to. These basic standards specify the acoustical requirements for measurements appropriate for different test environments and accuracies. It is important that specific test codes for various types of machinery and equipment be established and used in accordance with the requirements of these basic International Standards. Such standardized noise test codes will recommend the basic International Standard(s) to be used and will give detailed requirements on mounting and operating conditions for a particular family to which the machine under test belongs. If no specific noise test code exists for a particular type of machinery, this International Standard is of use for the choice of the most suitable of the basic standards. In all cases, the mounting and operating conditions of the machine under test should be in accordance with the general principles given in the basic standards. NOTE Two quantities which complement each other can be used to describe the sound emission of machinery or equipment. 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 the work station and at other specified positions are the series ISO 11200 to ISO 11204.