This standard specifies the test method for determining the impact resistance of rigid plastic sheets using the falling weight method. The core principle involves a striker (falling weight) of known mass and shape, falling freely from a specific height to deliver a single impact to a horizontally clamped specimen. By systematically adjusting the impact energy (by changing the mass or height of the falling weight) and testing a set of specimens, the median failure energy required to cause failure in 50% of the specimens is calculated, serving as a quantitative characterization of the material's impact resistance. The relevant testing instrument is a falling weight impact tester designed in accordance with this standard. Such equipment typically includes a high-stiffness frame, a falling weight system capable of precise lifting and release, a dedicated annular clamping plate for firmly securing the specimen, and safety protection devices. The tester can automatically record impact parameters and calculate the final results, providing a standardized testing method for evaluating the impact toughness of sheets.