We perform absolute transmission scans on every melt of glass we purchase, recalculating the thicknesses required for each absorptive layer. This ensures an accurate match despite subtle variations between melts. The IL1710 system relies on a W quartz diffuser to provide accurate cosine correction. The IL1410 system integrates the silicon photodiode, Y filter, and a flashed opal diffuser in a low profile package that provides an excellent cosine response in an easy to handle probe. Both systems can measure the extremes of photometric illuminance, from starlight to sunlight, with microprocessor controlled autoranging.
Illuminance is defined as the amount of visible light per unit area falling on a surface.
International Light offers a number of photometric detectors with slightly different features, such as luminance optics or scotopic filtering. Consult a sales engineer for further assistance.