BS/EN 207-2017 pdf download.Personal eye-protection equipment Filters and eye-protectors against laser radiation (laser eye-protectors).
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 300 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 he measured for each laser wavelength during the exposure to laser radiation.
The values of energy density (H) in Table I for testing the resistance against laser radiation for pulsed lasers (1, R, M) shall be multiplied with the factor N’14, 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 d63 of the laser beam during this test shall be (1 ± 0,1) mm. The diameter dh3 is the area of
the smallest circle containing 63 % of the laser power/energy.
For pulse durations < 1 ns, the diameter d63 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 D. 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 v 5 Hz shall be used to test condition D.
If additional protection against pulsed lasers is required, the filters and laser 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 167:200 1.
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 ClauseS of EN 167:2001.
Thin film fitters should be carefully examined for defects (scratches and holes) as damage of deposited layer can affect protection against laser radiation.
4.6.2 Diffusion of light
The test shall be carried out in accordance with Clause 4 of EN 167:200 1.
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 LJV radiation
The test shall be carried out in accordance with Clause 6 of EN 168:200 1, with the lamp running at a power of 450 W and an exposure time of (50 ± 0,2) ii.
4.7.2 StabIlity to elevated temperature.BS/EN 207-2017 pdf download.
BS/EN 207-2017 pdf download
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