2021-12-11

An important detail parameter of the electric heating tube is the surface power. If the resistivity is too large, after a certain current is passed in, the surface power will be large; if the resistivity is too small, after a certain current is passed in, the surface power will also be small. The size is determined by the size of the resistance, and we can judge the current size by the change of the surface temperature.

Test the surface temperature of the heating tube to see the color of the heating wire. As the temperature rises, it changes from dark red to bright red, and then from close to yellow to white, reaching a dazzling blue-white color. Based on this fact, the temperature of the object can be judged from the color of the object's light emission. The single-head electric heating tube has a higher temperature (1100°C) and is yellow-red. The electric heating tube has a higher temperature (1300°C) and is yellowish-white. Achieve dazzling blue-white (1500°C) or above. So testing the surface temperature of an electric heating tube is actually to watch its color change.

The greater the current in the electric heating tube, the higher the temperature of the electric heating tube. On the contrary, the smaller the current in the electric heating tube, the lower the temperature of the electric heating tube. Therefore, you can simply judge the current size based on the surface temperature based on experience.