In the process of operation, because the electric heating element has a large specific resistance, it is heated in the air, and the temperature of the heating surface of the element reaches 1050 degrees, the resistivity is 600-1400mm2/m. The resistance value increase with the temperature gradually increased, in order to adhere to the normal temperature, the voltage should be progress. When the voltage is up to the maximum limit of the transformer, which can not meet the requirements, the method can be used to change the connection of molybdenum rods.

In the operation process of molybdenum rod, a single element for some reason damaged, we should increase the situation according to the time element resistance, to choose suitable component of complement resistance, not any new elements to replace. If the tungsten rod element is badly damaged or the increased resistance is too large, which can not reach the required temperature, it is better to replace it with new components. The replaced component should test the resistance value again, resistance distribution used in the low temperature region.