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TGA Formulas (LMA100P)
TGA (Thermal Gravimetric Analysis)
mode provides the capability of distin-
guishing two components of a sample
material by heating at two different
temperatures and calculating their
individual percent of total composition�
Drying conditions are programmed
where component one is evolved at
Temperature 1 (Cycle 1) and the second
component at Temperature 2 (Cycle
2)� When the slope conditions of Cycle
1 are met, the analyzer prints the first
percent calculation and then ramps to
Temperature 2� When the same slope
conditions are met for the second cycle,
the analyzer prints the second percent
calculation� Finally, a total percent is
calculated and printed� To achieve this
drying procedure, parameters for Temp
1, Time 1, Temp 2, Time 2 and Slope
must be set�
To set the TGA parameters:
§ From the main standby screen, press the
Setup soft key�
§ From the Setup Menu, press the 1 key
for Program Manage�
§ From the Program Manage menu,
press the 2 key for Create new program
if creating a new program or the 1 key
for Edit current program to edit an
existing program�
§ From the Program menu, enter values
for Temp 1, Time 1, Temp 2, Time 2
and the Slope�
§ To turn the TGA mode On, press the
1 key for Units followed by either 8 key
for TGA moisture or the key for TGA
volatiles� See formulas below to select
correct TGA formula� Press the Arrow
soft key to return to the Program menu�
§ If desired, press the 0 key for Program
Name to change the program name�
§ Press the Save soft key to save the
changes�
Note
The settings Temp 1, Time 1, Temp 2,
Time 2, Slope and Units: TGA moisture
or volatiles must be set for the TGA
mode to operate�
Selection for units of either moisture
or volatiles will change component
two (Cycle 2) calculation� When “TGA
Volatiles” is selected, each component’s
loss will be calculated as a percent of
the initial sample weight� When “TGA
moisture” is selected, each component
loss will be calculated as a percent of
that cycle’s initial weight� The follow-
ing equations are used for calculations:
(IW=Initial Weight, FW=Final Weight)
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