Thermogravimetric analysis

Thermogravimetric analysis

Thermogravimetric Analysis or TGA is a type of testing that is performed on samples to determine changes in weight in relation to change in temperature. Such analysis relies on a high degree of precision in three measurements: weight, temperature, and temperature change. As many weight loss curves look similar, the weight loss curve may require transformation before results may be interpreted. A derivative weight loss curve can be used to tell the point at which weight loss is most apparent. Again, interpretation is limited without further modifications and deconvolution of the overlapping peaks may be required.

TGA is commonly employed in research and testing to determine characteristics of materials such as polymers, to determine degradation temperatures, absorbed moisture content of materials, the level of inorganic and organic components in materials, decomposition points of explosives, and solvent residues. It is also often used to estimate the corrosion kinetics in high temperature oxidation.

Analyzer

The analyzer usually consists of a high-precision balance with a pan (generally platinum) loaded with the sample. The pan is placed in a small electrically heated oven with a thermocouple to accurately measure the temperature. The atmosphere may be purged with an inert gas to prevent oxidation or other undesired reactions. A computer is used to control the instrument.

Analysis is carried out by raising the temperature gradually and plotting weight against temperature. The temperature in many testing methods routinely reaches 1000°C or greater, but the oven is so greatly insulated that an operator would not be aware of any change in temperature even if standing directly in front of the device. After the data is obtained, curve smoothing and other operations may be done such as to find the exact points of inflection.

A method known as hi-res TGA is often employed to obtain greater accuracy in areas where the derivative curve peaks. In this method, temperature increase slows as weight loss increases. This is done so that the exact temperature at which a peak occurs can be more accurately identified. Several modern TGA devices can vent burnoff to a fourier-transform infrared spectrophotometer to analyze composition.

Gallery


Wikimedia Foundation. 2010.

Игры ⚽ Поможем сделать НИР

Look at other dictionaries:

  • derivative thermogravimetric analysis — diferencialinė termogravimetrija statusas T sritis Standartizacija ir metrologija apibrėžtis Metodas kaitinamos medžiagos masės kitimo spartai matuoti. atitikmenys: angl. derivative thermogravimetry; derivative thermogravimetric analysis;… …   Penkiakalbis aiškinamasis metrologijos terminų žodynas

  • differential thermogravimetric analysis — diferencialinė termogravimetrija statusas T sritis Standartizacija ir metrologija apibrėžtis Metodas kaitinamos medžiagos masės kitimo spartai matuoti. atitikmenys: angl. derivative thermogravimetry; derivative thermogravimetric analysis;… …   Penkiakalbis aiškinamasis metrologijos terminų žodynas

  • Differential thermal analysis — Acronym DTA Classification Thermal analysis Other techniques Related Dynamic mechanical analysis Thermomechanical analysis Thermogravimetric analysis Differential thermal analysis Dielectric thermal analysis Differential thermal an …   Wikipedia

  • List of materials analysis methods — List of materials analysis methods: Contents: Top · 0–9 · A B C D E F G H I J K L M N O P Q R S T U V W X Y Z μSR see Muon spin spectroscopy …   Wikipedia

  • Dynamic mechanical analysis — Dynamic Mechanical Analyzer Acronym DMA Classification Thermal analysis Manufacturers Bose Electroforce Group, Mettler Toledo, Netzsch Instruments, PerkinElmer, TA Instruments, Triton Technology Ltd, Gabo Other techniques Related Isothermal… …   Wikipedia

  • Thermal analysis — is a branch of materials science where the properties of materials are studied as they change with temperature. Techniques include: *Differential scanning calorimetry *Dynamic mechanical analysis *Thermomechanical analysis *Thermogravimetric… …   Wikipedia

  • TGA — Thermogravimetric Analysis Contributor: CASI …   NASA Acronyms

  • Analytical chemistry — For the journal, see Analytical Chemistry (journal). Analytical chemistry is the study of the separation, identification, and quantification of the chemical components of natural and artificial materials.[1] Qualitative analysis gives an… …   Wikipedia

  • Atmospheric reentry — refers to the movement of human made or natural objects as they enter the atmosphere of a planet from outer space, in the case of Earth from an altitude above the edge of space. This article primarily addresses the process of controlled reentry… …   Wikipedia

  • Differentialthermogravimetrie — diferencialinė termogravimetrija statusas T sritis Standartizacija ir metrologija apibrėžtis Metodas kaitinamos medžiagos masės kitimo spartai matuoti. atitikmenys: angl. derivative thermogravimetry; derivative thermogravimetric analysis;… …   Penkiakalbis aiškinamasis metrologijos terminų žodynas

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”