The furnace's temperature can be changed continuously, stays the same, and the instrument is simple to use. Teflon is applied to the entire machine's surface to safeguard experimenters' and equipment safety and resist strong acid and alkali corrosion. Technology for detecting heating elements and triggering an automatic alarm in an abnormal situation. - The temperature in the furnace is continuousJy adjustable, the temperature is constant, and the instrument is easy to operate. - The surface of the whole machine is sprayed with Teflon, which is resistant to strong acid and alkali corrosion, and - protects the safety of experimenters and equipment. - Heating element detection technology, automatic alarm prompt for abnormal situation.