ASTM test methods surface arcs

Corrosion—While corrosion is usually not a concern on hot surfaces, recognize that all systems have shut down periods, with the probability that moisture will find ingress and condense. Many insulalions arc alkaline and have little adverse effect on iron and copper, but aluminum is affected adversely. A major concern is stress-corrosion of stainless steel induced by even trace amounts of soluble chlorides un ASTM Test Method maybe used. 

In most weathering devices, the approximate temperature of dark colored specimens is simulated and regulated with the use of a black panel sensor of either the uninsulated or insulated type described in ASTM G151 (61). It serves to control the air temperature which, in combination with the surface heat caused by absorbed radiation, provides the black panel temperature specified in the test method. The heat due to absorbed radiation depends on the visible and infrared absorption properties of the materials as well as on the SPD and irradiance of the source. Generally, the black panel temperature that specified is the maximum temperature that dark samples attain under use conditions. Currently, the highest black panel temperature specified is 89°C during the light-only period in a xenon arc device used for tests on automotive interior materials such as seat covers and dashboards (62). 

A large number of flammability tests have been developed to evaluate the ignition propensity of a wide range of materials exposed, usually for a short duration, to a small heat source. For example, the most recent compilation of ASTM lire standards includes 30 small heat source ignition tests.21 When adding methods that use an electric arc, hot wire, hot surface, etc., instead of a flame and those developed by other standard organizations (NFPA, UL, ISO, IEC, etc.), the total number of tests is in the hundreds. 

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