熱量天秤-熱重量変化と熱量変化の同時測定装置-の開発と応用
1982 年 9 巻 3 号 p. 89-95
詳細
1982 年 9 巻 3 号 p. 89-95
A new calorimetric thermobalance has been developed by combining a thermobalance, a conduction-type calorimeter and an infrared image furnace. Using this new apparatus, the simultaneous thermogravimetry and heat change measurement can be made from room temperature up to 1170K with high accuracy and by simple operation.
In principle, a specimen in a platinum cell is heated in such a manner that a constant temperature difference exists at all times between the specimen and the outer nickel box while the temperature of the outer box is precisely controlled by the infrared image furnace and a temperature controller. The time required for the specimen temperature to increase by 1, 2, 5 or 10K is measured by the calorimetric circuit, and is digitally recorded along with the specimen temperature and the weight change.
The new apparatus which is designed to maintain the specimen temperature nearly constant during the reaction has made it possible to identify each stage in the dehydration process of multihydrates such as CuSO4·5H2O and MgSO4·7H2O. This apparatus is superior to the conventional TG-DTA or TG-DSC simultaneous analyzer in terms of the accuracy of calorimetry, and the resolution of reaction. The measurement accuracy of specific heat, heat of transition and heat of fusion is within ±3∼5% for pure substances such as Zn, KNO3 and SiO2.
