Thermogravimetric Analysis (TGA)

TA Instruments SDTQ600 Thermo-Gravimetric Analyser

The TA Instruments SDTQ600 Thermogravimetric analyser can be used to perform both thermogravimetric and differential thermogravimetric analysis.

Principle

The principle of thermogravimetric analysis is the relationship between the weight and the rate of change in the weight of a material as a function of temperature or time in a controlled atmosphere. By using this principle, materials that show weight loss/gain due to decomposition, oxidation or dehydration could be characterized.

Strengths

• The instrument is capable of measuring weight changes that are associated with thermal transitions and reactions in materials over a temperature range of ambient to 1450°C
• A heating rate of 50°C/min up to 1000°C and 20°C/min up to 1450°C
• Based on metal melting standards, the heat flow accuracy and heat flow precision is recognized as being better than ±2%
• The ΔT sensitivity for the instrument is 0.001°C and while the weight sensitivity is 0.1 µg

Limitations

• Sample size is small, therefore the sensitivity to small mass loss effects is lost (A minimum weight of 20 mg is required for best results)
• Due to the size of the pan, the amount of sample to be analysed is limited by its density (i.e. it is difficult to load 20 mg of a really light sample)
• Cannot identify evolved products

Applications

• The instrument can be used to characterize materials to analyse their thermal stability/degradation
• To quantify volatiles/ moisture content
• Screening of additives
• To analyse vaporization or sublimation
• To analyse deformation of organic/inorganic mixtures with suitable standards
• To assess loss on drying, residue/filler content and to understand decomposition kinetics
• To estimate the lifetime of a product, to analyse the effect of reactive/corrosive atmospheres on materials etc.

Technical Specifications

• Temperature Range : Ambient to 1450 ˚C
• Heating Rate – Ambient to 1000 ˚C : 5 to 20 ˚C/min
• Heating Rate – 1000˚C to 1450 ˚C : 20 ˚C/min
• Thermocouples : Platinum/Platinum-Rhodium (Type R)
• Temperature Calibration : Curie Point or Metal Standards (1 to 5 Points)
• DTA Sensitivity : 0.001 ˚C
• Calorimetric Accuracy/Precision : ± 2% (based on metal standards
• Vacuum : to 7 Pa (0.05 torr)