Why is drift and precision data important?
A properly designed TGA instrument should be based on a reliable thermobalance:
- A low baseline drift under temperature scanning conditions is highly desirable for these experiments allowing large sample mass variations that do not require buoyancy effect corrections (baseline subtraction)
- A high baseline drift precision is required to ensure both repeatable measurements and bias-free data for these small sample mass variation experiments when baseline subtraction is necessary
Five repeated experiments were performed from 50 °C up to 1700 °C at a rate of 10 °C/min under helium flow of 20 mL/min. For these experiments, 170 µL alumina crucibles were used. These experiments were conducted using Setaram’s Highest Versatility balance.
The TGA signal baseline drift values at 1000 and 1700 °C for each 5 experiments were determined. Their averages were 34 µg and 46 µg respectively. Figure 1 shows an overlay of the raw experimental data in gray, and of their average in red. The dashed lines depict a +/- 3 µg precision area within which the 5 baselines are included.
The THEMYS balances benefit from the combination of a low baseline drift even up to the highest temperatures and a best-in-class precision better than +/- 3µg over the whole temperature range.
Note that these results were obtained under true, real-laboratory life conditions, and with a crucible that is representative of what is used during experiments.
SETARAM Instrumentation thermobalances are designed specifically for thermal analysis applications, and not just adapted from existing laboratory balances.