The heating principle of the oven

The basic principle of the oven is that the heating tube is energized to heat the air and food inside the oven, so the oven can, and need to preheat the empty box to reach the required temperature. The old model of the oven is used quartz tube, the new oven are used copper tube. Usually two copper tubes on the top and bottom of the oven, the volume is particularly large oven using W-shaped tube, increase the length of the heating tube to improve the heating efficiency. Heating tube only a power, when the oven reaches the desired temperature, the heating tube will cut off