| Popis: |
Corneal epithelial injury thresholds have been determined for exposures to 1.54 μm infrared radiation having durations from 1 to 100 sec and beam diameters from 0.5 to 7 mm. For 1 sec exposures, measured thresholds range from 12 W/cm 2 (5 mm diameter beam ) to 67 W/cm 2 (0.5 mm diameter). For 2 sec exposures, they range from 9 W/cm 2 (7mm diameter) to 57 W/cm 2 (0.5 mm diameter). For 10 sec exposures, they range from 3.7 W/cm 2 (7mm diameter) to 33 W/cm 2 (0.5 mm diameter). For 100 sec exposures, they are 1.4 W/cm 2 (7mm diameter) and 3.7 W/cm 2 (2mm diameter). The dependence of the measured thresholds on laser beam diameter provides strong evidence supporting a critical temperature damage model. These measured thresholds are greater than 10 times the maximum permissible exposure (MPE) in ANSI Z-136.5-2000. |
