Mezcla

Frequently
asked
questions

Thermogravimetric
Analysis (TGA)

A Beginner’s Guide
This booklet provides an introduction to the concepts
of Thermogravimetric Analysis (TGA). It is written for
scientists unfamiliar with TGA.

Pyris 1 TGA

TGA 4000

STA 6000

The Thermogravimetric Instrument Family

The Thermogravimetric Analyzer (TGA) is an essential laboratory tool used formaterial
characterization. TGA is used as a technique to characterize materials used in various
environmental, food, pharmaceutical, and petrochemical applications. PerkinElmer is the
leader in TGA. We have been manufacturing Thermal Analysis Tools since 1960, and no
one understands the applications of TGA like we do. In the following pages, we answer
common questions about what a TGA is, howthey work, and what they tell you.

Table of Contents
22 Common Questions about TGA
What is TGA?
What is the difference between the Pyris 1 TGA and TGA 4000?
How is a TGA Thermal Curve displayed?
What does a TGA Thermal Curve look like?
What can we learn from this TGA Thermal Curve?
What is reproducibility and why is it important?
When should I check the TGA calibration?
How do I cleanthe TGA furnace?
When and how do I clean the TGA furnace tube?
What is the best way to prepare a sample?
What temperature range should I run in?
What temperature scanning rate should I use?
What do I need to know about sample atmosphere?
When should I calibrate my TGA?
How do I calibrate my instrument?
TGA application curves
How can the TGA be used to compare two (2) similar products?
Howcan the TGA be used as a QA/QC tool to ensure products meet
their material specifications?
How can the TGA be used to ensure product safety?
Can the TGA be used to determine carbon content?
Can the TGA be used to identify counterfeit products?
Can the TGA be used to identify safe operating temperatures in various gases?
How can the TGA be used to enhance product formulation processes?
Howcan the TGA be used to reverse engineer a product?
How can I increase my laboratory’s productivity?
What should I do if I have a limited amount of sample and little time to fully
characterize the sample?
Simultaneous TGA-DSC application curve
What is evolved gas analysis?

3
4
4
4
5
7
7
7
8
8
8
9
9
10
10
11
12

Can TGA analyze Nanomaterials?

18

Conclusion
UsefulInternet Links
ASTM® Plastics TGA Methods
2

12
13
13
14
14
15
15
15
16
16
17

18
18
19

22 Common Questions about TGA
Q

What is TGA?

A

Definition: Thermogravimetric Analysis is a technique in which the mass of a
substance is monitored as a function of temperature or time as the sample specimen
is subjected to a controlled temperature program in a controlledatmosphere.
An Alternate Definition: TGA is a technique in which, upon heating a material,
its weight increases or decreases. A Simple TGA Concept to remember: TGA
measures a sample’s weight as it is heated or cooled in a furnace.
A TGA consists of a sample pan that is supported by a precision balance. That pan
resides in a furnace and is heated or cooled during the experiment. The mass of
the sampleis monitored during the experiment. A sample purge gas controls the
sample environment. This gas may be inert or a reactive gas that flows over the
sample and exits through an exhaust.
PerkinElmer offers two types of TGAs, a top-loading TGA 4000 and a bottomloading or hangdown, Pyris 1 TGA. The TGA 4000 supports the sample pan above
the balance via a “stem” support rod. The Pyris 1 TGAsupports the sample pan
via a “hangdown” below the balance. Both styles take advantage of gravity to
obtain very accurate and reproducible measurements.

TGA 4000.

Pyris 1 TGA.

These instruments can quantify loss of water, loss of solvent, loss of plasticizer,
decarboxylation, pyrolysis, oxidation, decomposition, weight % filler, amount of
metallic catalytic residue remaining on carbon...