Molten silica formers

At temperatures close to 20 20°, water is a suitable liquid for a thermostat. At higher temperatures it is more convenient to use a fluid such as silicone oil, or above 200°, molten metals. A typical furnace is shown in Fig. 5. A silica former is wound with nichrome wire such that the pitch decreases from one end to the centre and then increases again to the other end. Since heat losses are greatest at the ends this provides a rough correction. An inconel tube also evens out the tempera-... 

Molten silica (SiO2) is often considered the prototypical strong glass former (Angell, 1988). Its density is relatively constant in the supercooled range (<1700°C), and in that range the Arrhenius form (39) provides a good description for A numerical fit for that viscosity leads to the results (Mackenzie, 1961)... 

---