BS EN 207-2017 pdf free download.Personal eye-protection equipment Filters and eye-protectors against laser radiation (Iaser eye-protectors)
4.2 Spectral transmittance of filters and frames
T he spectral transm itt ance shall be determined for normal incidence. Filters with angu l ar -d ependent transmittance (such as interference layers) for the wavelength range from 400 nm to 1400 nm shall be measured at angles of incidence between
with polarized radiation and an orientation of the
polarization di rection giving the highest value of the spectral transm it tance. Filters with angulardependent transmittance for other wavelengths shall be measured at angles of incidence between and 90 0 with polarized radiation. In this case , the scale number results from the h ighest of the spectra l transmittance values measured.
Testing shall be done in accordance with EN 167:2001 , Clau se 6.
4.3 Luminous transmittance of filters
The luminous transmittance shall be determined for normal incidence , relative to the D65 standard iII um in ant (see ISO 11664-1:2007 and ISO 11664-2:2007)
T he test shall be performed according to EN 16 7:2001 , Clause 6.
4.4 Resistance of filters to laser radiation
The test shall be carried out with laser radiation ofthe specified wavelengths and the power and energydensities giv en in T able 1. The spectral transmittance shall be measured for each laser wavelength during the exposure to laser radiation.
T he values of energy density Table 1 for testing the resistance against laser radiation for pulsed lase rs shall be multiplied with th e factor N .l/ 4, where N is the numbe r 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 ofheadbands).
The di amet er d 63 of the laser beam during this test shall be (1 + 0 , 1) mm. The d iame ter d 63 is the area of the smallest circle containing 63 % ofthe laser powerjenergy .
For pulse durations < 1 ns , the diameter d6 3 of the laser b eam during this test shall mm .
In the case of rectangular beams , the dimensions spec ifi ed 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 re petition rates (<25 Hz). If it is not possible , the energy density used for test i ng shall be given and the product shall be marked in accor danc e with 6. 1 ,
d).
All laser protective filters and frames shall be tested in accordance with the t est condition D. lf commercia l1 y ava il able , test i ng at mode D shall be done with a real CW laser. If it is not feasible , testing sha l1 be done with a pulsed laser system at a minimum pulse V of Hz. If no
laser with pulse repetition rates higher than 25 Hz is available , a pulsed laser sys tem at a minimum pu lse repetition frequency of Hz shall be used to test condition D.
lf addit ional protection against pulsed lasers is requ i red , the filters and laser eye-protec tors sha ll be te sted according to one or severa l of th e test condit ions 1, R or M.
L asers which do not show spiking at the beginning of the em ission sha ll be used. The spatial a nd te mpo ra l beam pro fi1 e shall be documented , exce pt f or tem pora l pro fi1 es of M mode lasers.
4.5 Refractive value of filters and eye-protectors
The test shall be car J” ied out in accordance with Cl ause 3 ofEN 167:2001.
4.6 Quality of material and surface of filters
4.6.1 Material and surface defects
The tes t shall be carried out in accordance wi th Clause 5 of EN 167:200 1.
Thin film filt ers should be caref ully exam ined for defects (scratches and hol es) as dama ge of dep os it ed layer can affect protection again st l aser r ad iation.
4.6.2 Di ffus ion of light
The test sha l1 be carried out in accordance with Clause 4 of EN 167:200 1.
If the simplified method cannot be used becau se 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 sha ll be carr i ed out in accorda nce with Clause 6 of EN 168:2001 , with th e lamp running at a power of 450 W and an exposure time of (50 :t 0 , 2) h.
4.7.2 Stability to elevated temperature
Fil ters and eye-protectors shall be stored for at least 7 h in a climatÎC cabin et at a temperatu re of (55 + 2) oC and a relative humidity of> 60 %, and then sto r ed for at least 2 h at room tem peratu re.
4.8 Resistance of filters to ignition by contact with hot surfaces The test shall be carried out in accor dance with Clause 7 of EN 168:2001.BS EN 207 pdf download