Weather-o-meters

Optical Properties and Radiation Effects. Within the range of wavelengths measured (uv, visible, and near-ir radiation), Teflon PFA fluorocarbon film transmits slightly less energy than FEP film (29) (Table 6). In thin sections, the resin is colorless and transparent in thicker sections, it becomes translucent. It is highly transparent to it radiation uv absorption is low in thin sections. Weather-O-Meter tests indicate unlimited outdoor life. 

A number of laboratory procedures even more rapid than the accelerated Weather-o-meter have been described for the deterrnination of expected weatherabihty of coating asphalts. Research sponsored by the Asphalt Roofing Manufacturers Association describes a stepwise procedure to determine changes in the cmde asphalt source (see Asphalt). 

Stabilized with 0.2% amine antioxidant High Density Polyethylene. Extrusion grades of hlgh-denslty polyethylene protected by 2.5% channel type black of 19 my particle size were exposed In a Weather-O-Meter for 10,000 hours without any evidence of serious mechanical damage, as measured by low temperature brittleness and elongation tests. This represents the useful limit In our accelerated weathering test, since as described In an earlier paper,(2) fllm-like deposits form on... 

Figure 3.104 Effect of UV irradiation in a QUV Weather-o-meter on the tensile properties of PVF, PVDF and ETFE (a) tensile modulus b) tensile strength (c) break elongationJ i...

Resistance to Photochemical Reaction Initiated by U.V. Light (the sun). With the Introduction and acceptance of silicone sealants the stress tests have had to be made more stringent. Filters are removed from the Weather-O-Meter tests so some change can be noted in 6000 hours. Previously, sealants were considered good if performance changes were not significant after 250 hours. In fact, silicone sealants are now used to seal the test chamber of weather-simulating machines.—... 

Use of UV stabilizer permits 50% retention of elongation after 8000 hrs in Weather-O-Meter. The same stabilizer is proposed for application in geomembranes, PVC coated fabrics, flooring, wallcoverings, automotive trim. 

The Atlas Xenon Arc Weather-O-Meter is nsed according to ASTM D822-01 [123]/G155 [124]. In this cabinet the coated panel is exposed to a cycle of 102 minntes light, followed by 18 minutes light together with water spray. 

Table 5 Change of Properties on Exposure in Weather-O-Meter (black panel temperature 63°C)...

Weather-O-Meter exposure 10,000 h in carbon tensile strength - 93% retention, elongation -100% retention ... 

Weathering (9). Free films of commercially available silicone and polyurethane construction sealants were placed back-to-back in a frame where the films were separated with an aluminum divider. All of the free films were loaded into a xenon-arc Weather-o-meter (Atlas Electric Devices Company) for weathering. One series of films was thus exposed to light and water while the other was exposed to water only. The total time of exposure was 8000 hours. 

We may also mention the Weather-o-Meter which is similar. Other equipment can simulate corrosion with a salt spray, or simulate the aggressions from other agents such as chemicals. 

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