There are three types of thermogravimetric analyzers: suspension system, top-loading system and horizontal system.
Structures and Features
A sample is suspended from the analyzer.
A sample is placed above the analyzer.
A sample is placed at the edge of the analyzer.
Highly sensitive thermogravimetry
Wide range of measurable sample volumes
Simultaneous measurement of TG-DTA and TG-DSC
is not possible.
Direct measurements of sample temperatures are possible.
Can be applied as simultaneous measuring devices of TG-DTA and TG-DSC.
In general, baselines drift in TG analysis when temperatures fluctuate due to changes in buoyancy and convection by heating. (Weight signals change even if the amount of sample does not change superficially.) In order to avoid baseline drifts, analyzers with differential structures are often used in each system.
What is a Differential Structure?
The following image shows the structure of a top-loading differential analyzer.
As shown in the image, when a sample and a reference are placed on sample trays (temperature sensors) located at both edges of a beam and heated, a weight difference between the sample and the reference is detected as a signal. Since buoyancy and convection are applied equally to them, the force is offset to remove the baseline drift.