Thermogravimetric analysis (TGA) involves gradually heating a sample in a furnace while measuring its weight on an analytical balance. TGA is used to study weight changes that occur as the sample is heated, such as those from loss of volatile components. The document describes the basic principles and components of TGA instrumentation, including the furnace, balance, temperature programmer/controller, and recorder. Factors like furnace heating rate, sensor sensitivity, recording speed, sample amount, particle size, and heat of reaction can affect the precision and accuracy of the TGA curve.

1. Thermogravimetry
Analysis(TGA)
Presented by,
Miss Sujata Holkar
M.pharm 1st year
(Pharmacology)
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2. ◆Contents:-
1: Introduction
2: Principle
3: Instrumentation
4: The factors affecting the precision
and accuracy of theTG curve
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3. ◼ An Internationally accepted definition of
thermogravimetry is as follows:-
"It is a technique where by weight of substance in an
environment heated or cooled at a controlled rate, is
recorded as a function of time or temperature.”
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OR
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.
◆Definition

4. A TGA analysis is performed by gradually raising the
temperature of a sample in a furnace as its weight is
measured on an analytical balance that remains
outside of the furnace. In TGA, mass loss is observed
if a thermal event involves loss of a volatile
component.
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◆Principle:-

5. A.Recording balance
B.Sample holder
C.Furnace
D.Furnace temperature programmer/
controller
E.Recorder
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◆Instrumentation:-
◼ Components of
intrumentation

6. ◆ Block diagram ofTGA
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7. The basic requirements of a Balance are accuracy,
sensitivity, reproducibility and capacity.There are 2
types of balances
1) Null type balance which consists of a sensor which
detects the deviation from the null point and restores
the balance to its null point by means of a restoring
force.
2) Deflection balance which converts the deflection
of balance beam deflection into a suitable mass by
means of photographic recording or recording
electrical signals or using an electro-chemical device.
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1)Thermobalance:-

8. The Furnace provides linear heating over a wide range
of operating temperaures, typically -150 deg. Celsius to
about 2000 deg. Celsius depending on the requirement.
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2)Furnace:-

9. Temperature measurement and regulation is done with
the help of thermocouples. Usually 2 thermocouples
are used, where one records the temperature change,
the other actuates the control system.
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3)Furnace tempreture
programmer/controler:-

10. The recording unit makes use of a microprocessor
which allows for digital data acquisition and
processing using a personal computer.
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4)Recorder:-

11. 1) Furnace heating rate
2) Sensitivity of the sensors
3) Recording speed
4) Amount of sample
5) Particle size
6) Heat of reaction etc.
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◆The factors affecting the precision and
accuracy of theTG curve are

12. Thank you
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