scope:

This part of IEC 60068 provides standard procedures and guidance for conducting acoustic tests in order to determine the ability of a specimen to withstand vibration caused by a specified sound-pressure level environment to which it is, or is liable to be, subjected.

For sound pressure level environments of less than 120 dB acoustic tests are not normally required.

This standard determines the mechanical weakness and/or degradation in the performance of specimens and to use this information, in conjunction with the relevant specification, to decide on their acceptability for use. The methods of test may also be used as a means of establishing the mechanical robustness or fatigue resistance of specimens.

Two procedures are described for conducting tests and for measurement of the sound pressure levels within the acoustic noise field and considers the need for measurement of the vibration responses at specified points on the specimen. It also gives guidance for the selection of the acoustic noise environment, spectrum, sound pressure level and duration of exposure.

The progressive wave tube method is relevant to material where aerodynamic turbulence will excite part, or all, of the total external surface. Such applications include aircraft panel assemblies where the excitation exists on one side only. The reverberant chamber method is relevant where it is preferable to induce vibration onto the entire external surface of equipment by distributed excitation rather than fixed points by means of electro-dynamic shakers.