Compositional Analysis Using a New Symmetrical Microthermobalance

Buoyancy corrections are an important restriction for a precise evaluation of thermogravimetric results achieved with conventional thermobalances. A newly developed thermomicrobalance, designed symmetrically with respect to the arrangement of the balance, furnaces, and gas flow, eliminates buoyancy effects at the thermogravimetry (TG) signal. This instrument allows determination of very small mass changes over a wide range of temperatures. Sample weights in the microgram range result in short reaction intervals. The utility of the instrument for compositional analysis was demonstrated by studying the decomposition characteristics of CaC₂O₄·H₂O and CuSO₄·5H₂O, and the magnetic transition of nickel for temperature calibration.