ASTM C1257
ASTM C1257 – Standard Test Method for Accelerated Weathering of Solvent-Release-Type Sealants Description: Significance and Use 5.1 It is difficult to establish a precise correlation between laboratory accelerated and natural weathering because of (1) geographical climatic variations, local weather variation from normal, and local pollutants and (2) the fact that the acceleration factor is material dependent, varying with the type …