An important parameter of the heating wire is the surface power. The resistivity is too large, and the surface power is large after a certain current is applied. Therefore, for small power appliances, small diameter and small current are used, but the magnitude of the current is determined by the size of the resistor. The higher the current in the heating wire, the higher the temperature of the heating wire. The smaller the current in the heating wire, the lower the temperature of the heating wire. The length and diameter of the heating wire are calculated.
Look at the color of the heating wire, and change from dark red to bright red as the temperature rises, then turn from near yellow to white to achieve dazzling blue and white. According to this fact, the temperature of the object can be judged from the color of the object's illumination. The heating wire has a high temperature (1100 ° C) and is yellowish red. The heating wire has a higher temperature (1300 ° C) and is yellowish white. A dazzling blue-white (1500 ° C) or above.