BS EN 352-1:2020 pdf download
BS EN 352-1:2020 pdf download.Hearing protectors – General requirements Part 1: Earmuffs.
b) behind-the-head earmuffs
For each of the combinations of test dimensions shown by the letter M In EN 13819-1:2020, Table 2. the range of adjustment of the cups/headband and of the width between the cushions shall enable the earmuffs to be fitted to the fixture.
4.3.2.3 Small size range’ earmuffs
a) over-the-head and under-the-chin earmuffs
For each of the combinations oltest dimensions shown by the letter S in EN 13819-1:2020, Table 1, the range of adpustment of the cups/headband and of the width between the cushions shall enable the earmuffs to be fitted to the fixture.
b) behind-the-head earmuffs
For each of the combinations of test dimensions shown by the letter Sin EN 13819-1:2020, Table 2, the range of adjustment of the cups/headband and of the width between the cushions shall enable the earmuffs to be fitted to the fixture.
4.3.2.4 ‘Large size range’ earmuffs
a) over-the-head and under-the-chin earmuffs
For each of the combinations of test dimensions shown by the letter L in EN 13819-1:2020, Table I, the range of adjustment of the cups/headband and of the width between the cushions shall enable the earmuffs to he fitted to the fixture.
b) behind-the-head earmuffs
For each of the combinations of test dimensions shown by the letter L in EN 138 19-1:2020, Table 2. the range of adjustment of the cups/headband and of the width between the cushions shall enable the earmuffs to be fitted to the fixture.
4.3.3 Cup rotation
When tested In accordance with EN 138 19-1:2020, 4.3. the contact between the cushions and the plates of the fixture shall be continuous insofar as it provides an unbroken barrier between the inside and outside perimeter of the cushions.
4.3.4 Headband force
When tested in accordance with EN 13819-1:2020, 4.4, the headband force of each specimen shall not be greater than 14 N. In the case of earmuffs incorporating means to adjust this force, it shall be possible to adjust the force to 14 N or less. For universal earmuffs tests shill be performed for all wearing modes.
4.3,5 CushIon pressure
When tested in accordance with EN 13819-1:2020, 4.5, the cushion pressure of each specimen shall be not greater than 4 500 Pa. For earmuffs incorporating means to adjust the headband force. this requirement shall apply to the maximum force setting or 14 N, whichever is the lower.
4.3.6 Resistance to damage when dropped
Unless 4.3.7 is to be satisfied, the earmuffs (except for replaceable cushions) shall remain intact and fully functional as a passive hearing protection when tested In accordance with EN 13819-1:2020. 4.6. Neither shall any part of the earmuffs become detached, such that correct reassembly requires the use of either a tool or a replacement part.
4.3.7 Resistance to damage when dropped at low temperature (optional)
When tested in accordance with EN 13819-1:2020, 4.7. the earmuffs (except for replaceable cushions) shall remain intact and fully functional as a passive hearing protection. Neither shall any part of the earmuffs become detached, such that correct reassembly requires the use of either a tool or a replacement part If the requirements of this subclause are met, the information shall be supplied to the user with the earmuffs according to Clause 6 I), as appropriate.
4.3.8 Change in headband force (including optional water immersion with headband under stress)
The headband force of each specimen shall not change by more than ± 15 % from that reported according to 4.3.4 after the earmuffs have been subjected to the appropriate conditioning and tests specified in EN 13819-1:2020, 4.1.3.7 a) to I). If the headband force according to 4.3.4 was measured for more than one size adjustment, the ± 15% limit shall apply only to the size adjustment which gave the highest initial force. The comparison between the results before and after conditioning shall be performed for the headband force of each specimen separately. Additionally, and in all cases, the final headband force of each specimen shall not exceed 14 N. For universal earmuffs the test shall be performed In the over-the-head wearing mode only. If the test according to EN 13819-1:2020. 4.11, (headband under stress) has been done and the requirements of 4.3.8 of this document are met, the information according to Clause 6 e) shall be supplied to the user with the earmuffs.
4.3.9 Insertion loss
The standard deviations reported in accordance with EN 13819-2:2020, 4.1 shall not be greater than 4,0 dIl in four or more adjacent one-third-octave-bands, and not greater than 7,0 dB in any individual one-third-octave-band.
