BS EN 207:2009 pdf download – Personal eye- protection equipment — Filters and eye- protectors against laser radiation (laser eye-protectors)
4.2Spectral transmittance of filters and frames
The spectral transmittance shall be determined for normal incidence. Filters with angular-dependenttransmittance (such as interference layers) for the wavelength range from 400 nm to 1 400 nm shall bemeasured at angles of incidence between 0° and 30° with polarized radiation and an orientation of thepolarization direction giving the highest value of the spectral transmittance. Filters with angular-dependenttransmittance for other wavelengths shall be measured at angles of incidence between 0° and 9o° withpolarized radiation. In this case, the scale number results from the highest of the spectral transmittance valuesmeasured.
Testing shall be done in accordance with EN 167:2001,Clause 6.
4.3Luminous transmittance of filters
The luminous transmittance shall be determined for normal incidence, relative to the D65 standard illuminant(see lSO 11664-1:2007 and lsO 11664-2:2007).
The test shall be performed according to EN 167:2001,Clause 6.
4.4Resistance of filters and frames to laser radiation
The test shall be carried out with laser radiation of the specified wavelengths and the power and energydensities given in Table 1.The spectral transmittance shall be measured for each laser wavelength during theexposure 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 N1, 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 theexception of headbands).
The diameter d6 of the laser beam during this test shall be (1 ±0,1) mm.
For pulse durations < 1 ns, the diameter dg of the laser beam during this test shall be ≥ 0,5 mm.ln 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). f it is not possible, the energydensity 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. lf commerciallyavailable, testing at mode D shall be done with a real CW laser. If it is not feasible, testing shall be done with apulsed laser system at a minimum pulse repetition frequency v of v2 25 Hz. lf no laser with pulse repetitionrates higher than 25 Hz is available,a pulsed laser system at a minimum pulse repetition frequency ofv≥5 Hz shall be used to test conditionD.
lf additional protection against pulsed lasers is required, the flters and laser radiation eye-protectors shall betested according to one or several of the test conditions l,R or M.
Lasers which do not show spiking at the beginning of the emission shall be used. The spatial and temporalbeam profile shall be documented, except for temporal profiles of M mode lasers.
4.5Refractive value of filters and eye-protectors
The test shall be carried out in accordance with Clause 3 of EN 167:2001.
4.6Quality 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 layercan affect protection against laser radiation.
4.6.2 Diffusion of light
The test shall be carried out in accordance with Clause 4 of EN 167:2001.
lf the simplified method cannot be used because the spectral transmittance is too low, the basic method shallbe used.
4.7Stability to uv radiation and stability to elevated temperature
4.7.1Stability to UV radiation
The test shall be carried out in accordance with Clause 6 of EN 168:2001, with the lamp running at a power of450 wW and an exposure time of (50±0,2)h.
4.7.2Stability to elevated temperature
Filters and eye-protectors shall be stored for at least 7 h in a climatic cabinet at a temperature of (55±2)C℃and a relative humidity of > 60 %, and then stored for at least 2 h at room temperature.
4.8Resistance of filters and frames to ignition by contact with hot surfacesThe test shall be carried out in accordance with Clause 7 of EN 168:2001.