Electro-optical instruments and devices for measuring radiant energy and luminous intensity of light emitting diodes in scientific, industrial and photographic applications, namely, LED photometers, traffic signal light testers, color temperature meters, exposure meters, meter testing equipment, light filters, instruments for photometry and radiometry, namely, luminance meters, radiance meters, illuminance meters, irradiance meters, spectroradiometers, candle-power meters, optical lenses, con...