BS/EN 352-5-2002 pdf download.Hearing protectors Safety requirements and testing Part 5 : Active noise reduction ear-muffs.
This BS/EN 352-5 is concerned with active noise reduction (ANR) ear-muffs. It specifies additional constructional, design and performance requirements, methods of test, marking requirements and user information relating to the incorporation of the active noise reduction facility.
The requirements of this standard are intended to take account of the ergonomic interaction between the wearer, the device and, where possible, the working environment in which the device is likely to be used (see Annex ZA of this standard and EN 458)
2 NormatIve references
This European Standard incorporates by dated or undated reference, provisions from other publications. These normative references are cited at the appropriate places in the text and the publications are listed hereafter. For dated references, subsequent amendments to or revisions of any of these publications apply to this European Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the publication referred to applies (including amendments).
EN 352.1:2002, Hearing protectors – Gen
3 Terms and definitions
For the purposes of this European Standard me following additional terms and definitions to those of EN 352-
1:2002 (or EN 352-3:2002. as appropriate) apply:
active mode
operation of the ANR ear-muff with the ANR circuit switched on.
3.2
passive mode
operation of the ANR ear-muff with the ANR circuit switched off.
4 Requirements
4.1 General
Active noise reduction ear-muffs shall meet the requirements of EN 352-1 (or EN 352-3, as appropriate). Additional requirements are listed below.
4.2 Materials and construction
The electronic circuit of the ANR ear-muff shall meet the electrical safety and EMC requirements apprnpriate to this class of equipment.
4.3 Performance
4.3.1 General
Active noise reduction ear-muffs shall meet all the performance requirements of EN 352-1(or EN 352-3. as appropriate), including the minimum attenuation requirement in their passive mode. Additionally, the requirements specified in 4.3.2, 4. .3.3 and 4.3.4 shall be satisfied.
Specimens of ear-muffs shall be conditioned and tested as specified in 5.1.1 and 5.1.2. The scheme of testing shall be as specified in 5.1.3.
4.3.2 Active attenuation
The sound output levels of the four test samp’es shall be measured in accordance with 5.2 and reported in wearer information (6,1).
The highest level of the external test noise for which the sound pressure level at the subject’s ear remains linearly related to the external sound pressure level, for all subiects and samples tested, up to a maximum external sound pressure level of 110 dB, shall be determined in accordance with 5.3 and reported in wearer information (6.1). (]
4.3.4 Oscillation and acoustic malfunction
When tested in accordance with 4.3.2, none of the subjects shall have perceived sustained oscillation or acoustic malfunction (whistling or instability) when the ear-muff has been fitted in accordance with the manufacturers instructions.
5 Testing
5.1 Specimens, conditioning and scheme of testing
This scheme of testing is additional to that described in EN 13819-1. It shall be carried out on additional samples. Estimates of uncertainty shall be presented with results, according to Annex A.
5.1.1 SpecImens
Four pairs of ear-muffs shall be submitted for testing. The individual ear-muff cups shall be numbered 1 to 8.
Fresh batteries, if any are installed in the ear-muffs, shall be fitted for the tests.
5.1.2 Conditioning and testing atmosphere
All specimens shall be conditioned and tested in an atmosphere having a temperature of 22 °C ± 5 °C and a
relative humidity of not more than 85%, as required in EN 13819-1.
5.1.3 Scheme of testing
The eight ear-muff cups shall be tested for active attenuation as described in 5.2 and for linearity as described in 5.3
5.2 Active attenuation
The acoustic measurements for active noise reduction ear-muffs are under consideration. For the time being and because of the urgent need, such measurements may be carried out in accordance with test procedures described in Annex B.
5.3 Maximum Sound Pressure Level for linear operation
The acoustic measurements for active noise reduction ear-muffs are under consideration. For the time being and because of the urgent need, such measurements may be carried out in accordance with test procedures described in Annex B.BS/EN 352-5-2002 pdf download.