The PMA2121 Blue Light Safety detector indicates the effective irradiance weighted with the American Conference of Governmental Industrial Hygienists (ACGIH) Spectral Weighting Function for blue light hazard. Light sources that may produce a blue light hazard include: monochromatic and collimated lasers as well as collimated arc, or tungsten lamps (e.g. search lamps). Flash lamps generally do not present serious hazard because of the limited energy of the flash as compared to continuous sources.
To protect against retinal photochemical injury from chronic blue-light, the max. exposure limit for a source subtending less than 0.011 radian should not exceed 10mJ/cm2 per 10,000 seconds of exposure (approx. 2 hours 47 minutes). For exposure periods greater than 10,000 seconds the weighted irradiance should not exceed 1µW/cm2.
Typical blue light levels are:
150 W halogen lamp at 50 cm distance - 70 µW/cm2
150 W Xe arc lamp at 50 cm distance - 80 µW/cm2
40 W fluorescent tube at 2 m distance - 5 µW/cm2

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