AT421D Series Digital Charpy Impact Tester is used to determine the impact toughness of non-metallic materials such as rigid plastics, fiber-reinforced composite materials, nylon, glass, ceramics, cast stone, asbestos boards, electrical insulating materials, etc. It is suitable for notched and unnotched specimens. This instrument complies with the following international and industry standards: ISO: ISO 179; GB/T: GB/T 1043; JB/T: JB/T 8762; JJG 145. It features SCM control, LCD display, touch screen control, easy operation, accuracy and reliability. It automatically corrects energy loss caused by friction and wind resistance, eliminating the need for manual calculation and correction. It automatically calculates and displays impact energy and the mean value after the test is completed. Data can be stored on a USB disk and exported for editing and printing, ensuring accuracy and reliability. Technical Specifications Model: HY4251D-I / HY4251D-II Impact velocity: 2.9m/s / 3.8m/s Impact energy: (0.5J), 1J, 2J, 4J, 5J / 7.5J, 15J, 25J, 50J Impact center distance: 230mm / 380mm Pendulum angle: 150° / 160° Radius of striking edge: R=2±0.5mm / R=2±0.5mm Radius of jaw: R=1±0.1mm / R=1±0.1mm Inclined angle of striking edge: 30±1° / 30±1° Energy display resolution: 0.01J / 0.01J Jaw support spacing: 40, 60, 62, 70mm / 40, 60, 70, 95mm Power supply: AC220V 50Hz / AC220V 50Hz Dimensions: 420×260×630mm / 460×330×745mm Weight: 60kg / 70kg