The surface of the electric heating tube will appear black for many reasons:
1. First of all, it may be because the electric heating tube itself has been burned, so the surface will turn black. If this is the case, everyone should pay attention and do not continue to use this product.
2. It may be caused by abnormal power supply or frequent power outages. The electric heating tube in use is repeatedly blackened due to power outages or abnormal power supply affecting normal use. 3. It may be caused by the poor contact of the controller contact points and the poor contact between the power cord plug and the electric heating socket.
4. Oxidation caused by electric heating. After the electric heating tube is heated and used for a period of time, due to the influence of air or humid environment, some black objects will be produced on the surface due to oxidation, just like when the flame of a candle is used to burn stainless steel, Its surface will produce a layer of black substance. This situation is relatively common, and this black oxide is non-toxic, and the electric heating tube can continue to be used.
Therefore, when the electric heating tube is heated for a period of time, the surface appears black, and we need to determine what causes it. If it still has a resistance value and can still work, it means that it is only caused by oxidation; if there is no resistance value, it should be burned out.
