Patent ID: 6073500
Filing Date: 2000-06-13
Classification: G01N

Abstract:
A process of providing ultra accelerated natural sunlight exposure testing of sample materials and devices under controlled weathering conditions that include multiple concurrent levels of temperature and relative humidity at high levels of up to 100.times. of natural sunlight comprising:a) concentrating solar flux uniformly as concentrated uniform reflected UV/VIS light; using a multi-step dish reflector; andb) directing said concentrated uniform reflected light onto sample materials in a chamber of multiple concurrent levels of temperature and relative humidity to allow the sample materials to be subjected to accelerated irradiance exposure factors of from about 25 to 100 suns for a sufficient period of time of about 20.1 hours to about 10 days to provide a corresponding time of about at least a years worth of representative weathering of said sample materials; wherein in step a), concentrating said solar flux uniformly is accomplished by:i) using a tracking heliostat to continually direct sunlight onto a primary concentrator array, to provide a concentrated sunlight Gaussian shaped beam;ii) passing said concentrated sunlight Gaussian-shaped beam through an attenuator to provide a reduced and controlled intensity of concentrated sunlight Gaussian-shaped beam;iii) passing said concentrated sunlight Gaussian-shaped beam through an irradiance redistribution guide to redistribute the Gaussian-shaped beam from the primary concentrator to a more uniform profile on a plane located a distance behind the irradiance redistribution guide; andiv) passing said redistributed Gaussian-shaped beam onto a cold mirror; comprising: I) a front surface UV reflective coating capable of reflecting ultraviolet light and; II) a second surface visible light reflector capable of reflecting visible light and transparent to near infrared radiation or, III) a front surface UV/VIS reflective coating capable of reflecting ultraviolet and visible light.