This standard specifically specifies unified testing conditions for determining the tensile properties of plastic films or sheets with a thickness of less than 1 mm. It is an extension of the general principles and is typically not applicable to special materials such as foamed plastics. The core instrument for testing according to this standard is an electronic tensile testing machine, which must be capable of precisely controlling the tensile rate (e.g., 50 to 500 mm/min) and accurately recording force and displacement data. During testing, specimens prepared according to the standard are clamped in the machine's grips and stretched at a constant speed until fracture occurs, thereby determining key mechanical properties such as tensile strength and elongation at break. This provides a standardized method for evaluating the quality of film materials.