What do you mean by Thermogravimetry? | How Thermogravimetric Analyzer works?

Reading Time: 4 minutes

What is Thermogravimetric analyzer?

Thermogravimetric analysis or TGA is a technique where the mass (or weight) of a material is measured as a function of temperature or time while the sample is subjected to a controlled temperature program in a controlled atmosphere. [Earnest, ASTM STP 997 (1988)].

Thermogravimetric Analysis(TGA) is conducted on an instrument referred to as a thermogravimetric analyzer. A Thermogravimetric Analyzer (TGA) is a laboratory tool that is used for material characterization based on the above principle. TGA is a very useful and user-friendly laboratory technique to characterize materials of multiple requirements and application. A TGA is used in multiple industries and applications like Coal, Alternative Fuel, Food, Pharmaceutical, Petrochemical etc.

What is Thermogravimetric analysis?

Thermogravimetric analysis or thermal gravimetric analysis (TGA) is a method of thermal analysis in which the mass of a sample is measured over time as the temperature changes. Alternatively, it can also be defined as a technique in which upon heating a material, its weight increases or decreases. TGA measures the composition, purity, decomposition reactions, decomposition temperature, and absorbed moisture content of samples. It is a powerful and robust method to explore the thermal stability of a material. The instrument widely used for such applications is known as Thermogravimetric Analyzer.

Types of Thermogravimetric analysis (TGA)

There are three types of thermogravimetry:

  • Isothermal or static thermogravimetry: In this technique, the sample weight is recorded as a function of time at a constant temperature.
  • Quasistatic thermogravimetry: In this technique, the sample temperature is raised in sequential steps separated by isothermal intervals, during which the sample mass reaches stability before the start of the next temperature ramp.
  • Dynamic thermogravimetry: In this technique, the sample is heated in an environment whose temperature is changed in a linear manner.

As per as application also there are two kinds of Thermogravimetric Analyzer widely known. One is Micro TGA and the other is Macro TGA.

Theory of Thermogravimetry

Thermogravimetric Analyzer determines weight loss, including moisture, ash, volatile content, and Loss on Ignition(LOI) in various organic, Inorganic and synthetic samples. Weight change is measured as a function of temperature and time as samples are exposed to a temperature program in a controlled atmosphere. The multi-sample furnace design allows for simultaneous analysis of up to 29 samples in a single furnace.

The analysis starts when samples have been prepared along with a sample list and empty crucibles have been loaded into the sample carousel. After empty crucible weights are recorded and tarred, the user is asked to load samples. Once crucibles are loaded with samples, sample weights are recorded and the method-specific furnace temperature and atmosphere begin. One of three analytical gases (air, N2, or O2) is used to control the atmosphere inside the furnace during the course of analysis as per the designed program. Temperature, temperature ramp rate, atmosphere, and duration can be selected for every program step. ASTM standard methods for Moisture, Ash, and Volatiles are also available as pre-set methods.

The mass change of each sample is measured and monitored throughout the analysis. Crucibles are automatically located to the position above and lowered into the balance pedestal where sample weights are recorded. Percent mass change is reported at the end of each step of the analysis and the final result is been displayed after the end of the program design.

How does Thermogravimetric analyzer work?

In simple terms, a thermalgravimetric analyzer provides a sequential readout of material mass as a function of temperature and time. This is carried out by heating samples in a chosen atmosphere on a highly precise balance. Various temperature profiles can be programmed to suit different experiments,

Measuring the sample’s mass at regular intervals throughout the temperature profile yields a thermogravimetric curve where mass is plotted as a function of temperature or time. This characteristic curve is very useful for a user as it gives important insights of thermal decomposition; where elevated temperatures begin to break the sample down.

In which Industry it is most useful for its application.

Thermogravimetric Analyzer finds its applications in multiple industries and requirements. Environmental, food science, pharmaceutical, and petrochemical applications are the mainstay of Thermogravimetric Analysis. It can utilised for any application where thermal stability of a sample with respect to time is required. It is quite common in Proximate analysis of Coal, Metal material application, Carbon Capture, Polymer, Pharmaceuticals, Food and so on.

What is a thermogravimetric analysis used for?

Thermogravimetric Analysis is an analytical technique that is used to determine a material’s thermal stability and its a fraction of volatile components by monitoring the weight change that occurs as a sample is heated at a constant rate.

Difference between TGA and DSC

Understanding the fundamental thermal properties of a given material is an important aspect of material design and analysis. Techniques to explore a material’s thermal properties include thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and differential thermal analysis (DTA). TGA measures the weight change of a sample over a temperature range, DSC measures the heat flow of a sample over a temperature range, and DTA measures heat differences between a reference sample and a sample of interest over a temperature range.

From these individual techniques, we can determine the heat capacity, transition points, and thermal stability of a material. It can also be expressed as in TGA, the change in mass of the sample is measured with the increasing temperature while, in DTA, the temperature difference that builds up between the sample and a reference is measured and in DSC, the heat released during a chemical process is measured.

About Product Brand:

Precisa Gravimetrics AG, Switzerland

Precica AG have been manufacturing Balances since 1935 with renowned swiss quality and Precision and are Globally acknowledged as one of the leading balance manufacturing companies.

About Us:

Aimil Ltd. is a leading ISO 9001:2015 certified Company, with an all-India network of sixteen offices, staffed and managed by more than 850 professionals. With a focus on instrumentation and over eight decades of experience, the company offers a range of state-of-the-art products manufactured in India and from reputed overseas manufacturers, backed by local expertise and efficient pre & post-sales support.

Our Mission is “To provide Optimal Quality and Customer Service by innovation and integration of leading edge global technologies“.

We offer instruments in the field of Civil Engineering, Analytical & Industrial, and Electronic applications and also offer consultancy Services.

through our division, Advanced Technology & Engineering Services (ATES), Noise & Vibration Engineering Services (NVES),

Condition Monitoring Services.

We also provide equipment & software solutions in Healthcare through our division Hygea Healthcare.

For more details, you may visit www.aimil.com.

Leave a Reply

Your email address will not be published. Required fields are marked *