Hybrid microwave/conventionally heated calorimeter

The design and construction of a calorimeter in which the specimen may be heated by microwave radiation and/or hot air is described. The apparatus was used to examine the effect of microwave radiation on the melting of benzil (89 degrees C) and the solid-state phase transition of silver iodide (147 degrees C). Reproducibility of transition temperature determinations were within +/- 1 degrees C. No changes were observed for benzil but silver iodide exhibited an apparent reduction in transition temperature to around 120 degrees C in the presence of microwaves, which increased with the level of microwave irradiation. (c) 2005 American Institute of Physics.