BS EN 207-2009 pdf download.Personal eye- protection equipment Filters and eyeprotectors against laser radiation (laser eye-protectors).
3.9 Construction of filters and frames
Filters shall be constructed so that when tested In accordance with 4.4 followed by a visual inspection no splinters are detached from the side of the filter facing the eye. If the filters consist of several individual filters. they shall be assembled in such a way that they cannot be interchanged.
Filters shall not be interchangeable in the frame. An exception is possible if the protection to laser radiation Is determined only by the filter(s) and no part of the frame lies inside the protected range as defined below. In this case the marking of the eye-protector shall be on the filter(s) and there is no requirement for the frame to satisfy 3.3 on resistance to laser radiation.
The frame shall be designed so that no laser radiation can penetrate from the side. This requirement is met if for the horizontal angle range a from – 50° (nasal side) to + 90° (temporal side) the vertical angle range fi is protected within the following limit angles in degrees (°).
The upward limit of the protected range shall be:
The downward limit of the protected range shall be:
Testing shall be done In accordance with 4.10.
3.10 Mechanical strength of eye-protectors
3.10.1 Basic requirement
Filters for protection against laser radiation shall satisfy the requirement for minimum robustness as specified in 7.1.4.1 of EN 166:2001.
The frames of the eye-protectors shall satisfy the requirements of 7.1.4.2 or 7.2.2 of EN 166:2001.
3.10.2 Optional requirements
If the mechanical strength of filters and eye-protectors against laser radiation is required to satisfy more stringent requirements, the requirements specified in 7.1.4.2 or the requirements specified in 7.2.2 of EN 166:2001 shall be met.
4 Testing
4.2 Spectral transmittance of filters and frames
The spectral transmittance shall be determined for normal incidence, Filters with angular-dependent transmittance (such as Interference layers) for the wavelength range from 400 nm to 1 400 nm shall be measured at angles of incidence between 0° and 30° with polarized radiation and an orientation of the polarization direction giving the highest value of the spectral transmittance. Filters with angular-dependent transmittance for other wavelengths shall be measured at angles of incidence between 0° and 90° with polarized radiation. In this case, the scale number results from the highest of the spectral transmittance values measured.
Testing shall be done in accordance with EN 167:2001, Clause 6.
4.3 Luminous transmittance of filters
The luminous transmittance shall be determined for normal incidence, relative to the D65 standard Illuminant (see ISO 11664-1:2007 and ISO 11664-2:2007).
The test shall be performed according to EN 167:2001, Clause 6.
4.4 Resistance of filters and frames to laser radiation
The test shall be carried out with laser radiation of the specified wavelengths and the power and energy densities given in Table 1. The spectral transmittance shall be measured for each laser wavelength during the exposure to laser radiation.
The values of energy density (H) in Table 1 for testing the resistance against laser radiation for pulsed lasers (I, R, M) shall be multiplied with the factor N’1’4. where N is the number of pulses in 5 s.
The frame shall be exposed to radiation at the point of least thickness for each of the materials used (with the exception of headbands).
The diameter cI of the laser beam during this test shall be (1 ± 0,1) mm.
For pulse durations c I ns. the diameter d of the laser beam during this test shall be 0.5 mm.
In the case of rectangular beams, the dimensions specified apply to the shortest side of the rectangle.
The duration of the test shall be taken from Table 4.
For pulsed lasers, testing shall be done with low repetition rates (≤ 25 Hz), If it is not possible, the energy density used for testing shall be given and the product shall be marked in accordance with 6.1. d).
All laser protective filters and frames shall be tested in accordance with the test condition 0. If commercially available, testing at mode D shall be done with a real CW laser. If it is not feasible, testing shall be done with a pulsed laser system at a minimum pulse repetition frequency v of v 25 Hz. If no laser with pulse repetition rates higher than 25 Hz is available, a pulsed laser system at a minimum pulse repetition frequency of i’ 5 Hz shall be used to test condition D.
If additional protection against pulsed lasers is required, the filters and laser radiation eye-protectors shall be tested according to one or several of the test conditions I, R or M.
Lasers which do not show spiking at the beginning of the emission shall be used. The spatial and temporal beam profile shall be documented, except for temporal profiles of M mode lasers.
4.5 Refractive value of filters and eye-protectors
The test shall be carried out in accordance with Clause 3 of EN 167:2001.
4.6 Quality of material and surface of filters
4.6.1 Material and surface defects
The test shall be carried out in accordance with Clause 5 of EN 167:2001.
NOTE Thin film filters should be carefully examined for defects (scratches and holes) as damage of deposited layer
can affect protection againsi laser radiation,
4.6.2 Diffusion of light
The test shall be carried out in accordance with Clause 4 of EN 167:2001.
If the simplified method cannot be used because the spectral transmittance is too low, the basic method shall
be used.
4.7 StabIlity to UV radiation and stability to elevated temperature
4.7.1 Stability to UV radiation
The test shall be camed out in accordance with Clause 6 of EN 168:2001. with the lamp running at a power of 450 W and an exposure time of (50 ± 0,2) h.BS EN 207-2009 pdf download.
BS EN 207-2009 pdf download
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