BS EN 352-1:1993 Hearing protectors. Safety requirements and testing - Part 1. Ear muffs
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Printed version of this standard is available at Library. To request, please e-mail to referencepk@usm.my and include a copy of this record in your e-mail.
This Part of the standard is concerned with ear-muffs and specifies constructional, design and performance requirements, methods of test, marking requirements and user information.
It calls for information to be made available concerning the sound attenuation characteristics of the ear-muffs measured in accordance with EN24869-1, and defines a minimum level of attenuation required for compliance with this specification.
This Part of the standard does not deal with ear-muffs for attachment to a helmet or which are part of a helmet. Neither does it deal with the performance of electronic devices which may be incorporated within ear-muffs nor amplitude sensitive ear-muffs.
This standard does not deal with the performance of hearing protectors to impulsive noise.
The sizing requirements in the standard enable the great majority of the industrial population to be fitted satisfactorily by “Normal size range” size ear-muffs. Populations of other sizes may be accommodated by “Small/Large size range” size ear-muffs, which are required to be accompanied by information regarding the range of sizes which they are designed to fit.
The requirements and tests of the standard are concerned primarily with physical performance. However, the standard also calls for the values of sound attenuation afforded by the ear-muffs, as measured in accordance with EN 24869-1, to be provided in order to assist purchasers in selecting the most appropriate type of ear-muffs for their needs, and minimum values of sound attenuation are specified. A maximum variability in insertion loss, measured objectively after a series of performance tests, is specified.
The objective method is defined in ISO/TR4869-3. It only facilitates the making of comparative measurements and insertion loss values obtained from its use will differ from the sound attenuation values measured using the procedures given in EN24869-1. The latter, which require the ear-muffs to be tested whilst being worn by human test subjects, is regarded as providing the reference test method for the measurement of the acoustic performance of hearing protectors.
