vacuum thermobalance [`vak·yǝm ¦thǝr·mō`bal·ǝns] ANALYTICAL CHEMISTRY An instrument used in thermogravimetry consisting of a precision balance and furnace that have been adapted for continuously measuring or recording changes in weight of a substance as a function of temperature; used in many types of physicochemical reactions where rates of reaction and energies of activation for vaporization, sublimation, and chemical reaction can be obtained. |