The muffle furnace is a general-purpose heating device. It can be divided into box furnace, tube furnace and crucible according to the shape of the appearance. The classification of the muffle furnace can be based on the heating element, the rated temperature, and the controller. Classification, see below: According to the heating elements, there are: electric furnace muffle furnace, silicon carbon rod muffle furnace, silicon molybdenum rod muffle furnace;