GB/T 2951.12-2008 "General Test Methods for Cable and Optical Cable Insulation and Sheath Materials, Part 12: General Test Methods for Heat Aging Test Methods" specifies the heat aging test method for cable and optical cable polymer insulation and sheath materials. This part of the standard applies to a variety of common insulating materials, including resilience, polyvinyl chloride (PVC), polyethylene (PE) and polypropylene (PP). The heat aging test is designed to evaluate the durability of materials in high temperature environments. Reliability and Stability in practical applications are ensured by exposing materials to specified high temperatures and measuring changes in their performance. Miscellaneous-related test methods are referenced in the standard to ensure the comprehensiveness and accuracy of the test.