A common 10-cm Pyrex infrared gas phase cell can be heated to a temperature of about 250°C under a vacuum of 10<sup>−4</sup> Torr if the crystal windows are sealed to the cell body with silicone rubber. A double-beam, forced-air circulation chamber or oven has been designed and constructed so that such cells can be used to obtain compensated high-temperature infrared spectra. The temperatures of both the sample and reference cells are essentially identical since the forced circulation in the oven achieves a thermal homogeneity over the whole interior of the oven. The temperatures of the cells may be raised or lowered relatively rapidly without damage.
H. W. Wilson, "A Simple, Evacuable, Double-Beam Infrared Hot Cell Assembly," Appl. Spectrosc. 24, 6-8 (1970)