Tube furnaces are equipped with a working tube which also serves as support for the heating wires. Thus, the working tube is part of the heating furnace with the inherent advantage of very high heat-up rates. More elaborate tube furnaces have two (or more) heating zones useful for transport experiments. Advanced materials in the heating elements, such as molybdenum disilicide offered in certain models can now produce working temperatures up to 1800 °C. If protective gas atmosphere is required, a separate working tube including gas supply system, e.g. made of quartz glass, can be inserted in the working tube.