ABSTRACT
In many heating elements the resistance material never becomes red hot. In such cases several metals and alloys in addition to the conventional resistance heating alloys can be used successfully. The low-resistivity materials are often used for very long heating elements and/or low voltages. Alloys with a large temperature factor of resistance often have a low oxidation resistance. The temperature dependence of the resistance is much stronger than for the resistance heating alloys. The wire may be insulated with different types of enamel coatings, which stand a maximum temperature of 100 to 220°C, depending on type of enamel. The high temperature factor of resistance results in a high inrush current and fast heating up, just as described for the halogen tubular heater. The low one applies for a temperature close to room temperature, whereas the higher value corresponds to a temperature often near the maximum temperature of application.
