STP1294

    Parametric Control of a Fresnel Reflecting Concentrator Outdoor Accelerated Weathering Device

    Published: Jan 1996


      Format Pages Price  
    PDF Version (320K) 16 $25   ADD TO CART
    Complete Source PDF (4.7M) 16 $55   ADD TO CART


    Abstract

    Outdoor accelerated weathering testing of materials using fresnel reflecting concentrators was pioneered by DSET in 1960. This type of testing is described in “Practice for Performing Accelerated Outdoor Weathering of Nonmetallic Materials Using Concentrated Natural Sunlight” (ASTM G90) and “Accelerated Exposure of Automotive Exterior Materials Using a Solar Fresnel Reflective Apparatus” (SAE J1961). The advantage of this form of accelerated weathering is that the sun's natural solar energy spectrum is used to irradiate the specimens under test. Since this is an outdoor method, variations in test conditions occur due to the natural seasonal weather differences. These seasonal variations mimic what occurs in the real world and correlation between real time weathering and outdoor accelerated weathering can be obtained for most materials with the traditional test cycles. However, advances in paint technology may require test cycles different than those specified by current test standards. The characteristics of modern, stabilized coatings indicate that they are now more resistant to the effects of both real time and accelerated weathering. Still, some failures occur in the real world that are not predicted by accelerated weathering tests. This paper will discuss the temperature and moisture control methodologies evolved over the last three years for a type of fresnel reflecting concentrator designated as “EMMAQUA®+”, an outdoor accelerated weathering test device, and the development of new test cycles for this device. This test device can simultaneously control black and white panel temperatures and provide several different moisture delivery methods. Data will be presented that will compare the results obtained with the new test cycles to the traditional cycles and to real time exposures.

    Keywords:

    outdoor accelerated weathering, fresnel concentrator, ultraviolet radiation


    Author Information:

    Putman, WJ
    Vice President Quality Assurance and Research, Manager of Evaluation Services, and Manager of EMMAQUA® Weathering, DSET Laboratories, Phoenix, Arizona

    McGreer, M
    Vice President Quality Assurance and Research, Manager of Evaluation Services, and Manager of EMMAQUA® Weathering, DSET Laboratories, Phoenix, Arizona

    Pekara, D
    Vice President Quality Assurance and Research, Manager of Evaluation Services, and Manager of EMMAQUA® Weathering, DSET Laboratories, Phoenix, Arizona


    Paper ID: STP16151S

    Committee/Subcommittee: G03.01

    DOI: 10.1520/STP16151S


    CrossRef ASTM International is a member of CrossRef.