Environmental
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LI-COR Photometric Sensors
The LI-210 Photometric Sensor is designed to measure illumination in terms of lux (1 footcandle=10.764 lux). This is radiation as the human eye sees it. If you are interested in the spectral response, a chart is provided here. (9K)
Although characteristics of the human eye vary from person to person, standard luminosity coefficients for the eye were defined by the Commission Internationale de Eclairage (C.I.E., International Commission on Illumination) in 1931. An absolute "sensitivity" figure established for the standard eye relates photometric units and radiant power units. At 5550 angstroms (555nm) the wavelength of the maximum sensitivity of the eye, one watt of radiant power corresponds to 680 lumens.
The sensitivity of the eye outside the wavelength limits defined by the C.I.E. is very low but not exactly zero. Studies with intense infrared sources have shown that the eye is sensitive to radiation of wavelengths at least as long as 10500 angstroms.
The LI-210 measures visible radiation and has a spectral response curve equal to the human eye. This curve is known as the C.I.E. Standard Observer Curve and is matched by the LI-210 to within 5% under most light sources. The LI-210 is commonly used in architectural and daylighting studies.
Bibliography
Please submit your LI-210 published papers or links to your websites to be featured here by contacting the Product Manager, Mr. Chris Mantzios.
