The tube furnaces all adopt high-performance, energy-efficient new-type electric furnaces, available in various models such as single-tube, double-tube, horizontal, openable, vertical, single-temperature zone, dual-temperature zone, and three-temperature zone. They are widely used for sintering or annealing new material samples under vacuum or inert gas protection. The furnace chamber is made of internationally advanced lightweight alumina ceramic fiber, offering excellent thermal insulation, lightweight and high-temperature resistance, resistance to extreme thermal shock, no cracking, no crystallization, no slagging, and no risk of contaminating the fired products. The energy-saving effect is 60%-80% compared to old-type electric furnaces.