Negatoscopes

-used for reading Rö films. Since the radiologist spends a lot of time in front devices for reading Rö films, it is necessary that the light source of these devices be of high quality. For these reasons, IEC standards define how the illuminated surface of these devices should be. IEC standards stipulate that the illuminance density in the center of the illuminated surface should not be less than 2000 cd/m2 and that the deviation of the lighting intensity at 5 cm from the edge in relation to the center should not be greater of 30%.