SEDL / STP / STP1369-EB / STP14349S

Temperature Measurements in TGA

Kelsey, M
Mettler-Toledo, Inc., Columbus, OH

Foreman, J
Mettler-Toledo, Inc., Columbus, OH

Pages: 10    Published: Jan 2000

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Abstract

The temperature of the specimen in thermogravimetric analysis (TGA) is affected by several factors, including specimen mass and heat capacity, transitions in the material, crucible mass and material of construction, and furnace response. Because many thermogravimetric analyzers have a thermal sensor that is separated from the specimen, differences in specimen conditions have no effect on the observed temperature. In this situation, the temperature sensor is calibrated by synchronization to an observed material transition. By using a TGA with a direct contact thermal sensor this study shows that the above effects have significant temperature implications. Furthermore, only by using a TGA with direct-contact temperature sensing can one observe the true sample temperature during a specimen mass change or other transition.