TA I
NSTRUMENTS
TGA 2950
B–19
Hi-Res
TM
Option
Unresolvable
Transitions
The Hi-Res
TM
techniques provide useful tools to
improve transition resolution of many sample
materials, but some materials will show little or
no resolution improvement. This is because
these materials have transitions which cannot be
separated by time and temperature alone. The
transitions are usually overlapped such that the
components of interest decompose at or very
near the same temperature and at approximately
the same rate of reaction. For these materials it
may be necessary to employ other techniques
separately or in conjunction with TGA, such as
vacuum, switching purge gases, semi-pressur-
ized sample containment, or evolved gas analy-
sis.
There are some general rules-of-thumb which
will help you decide if the material you are
working with will be a successful candidate for
resolution improvement. First, do the compo-
nents of the sample material decompose at
sufficiently different temperatures? This can
often be determined by running a slow heating
rate survey scan of the material at 1
°
C/minute
and comparing the result to a 20
°
C/minute scan
of the same material. Generally, the tempera-
tures of transition will be lower in the slower
scan, but if there is no observable improvement
in separation of the components, then it is likely
that Hi-Res
TM
TGA will not produce a signifi-
cant separation of the components either.
Always consider purge gas to be a factor when
running survey scans or heating rate trials.
Generally, nitrogen and air are the most com-
mon choices for purge. In some cases, transi-
tions which appear to be one large weight loss in
Summary of Contents for TGA 2950
Page 20: ...TA INSTRUMENTS TGA 2950 xx ...
Page 22: ...Introducing the TGA 2950 TA INSTRUMENTS TGA 2950 1 2 ...
Page 36: ...TA INSTRUMENTS TGA 2950 Installing the 2950 2 2 ...
Page 90: ...Running Experiments TA INSTRUMENTS TGA 2950 3 24 ...
Page 92: ...Technical Reference TA INSTRUMENTS TGA 2950 4 2 ...
Page 112: ...Technical Reference TA INSTRUMENTS TGA 2950 4 22 ...
Page 136: ...TA INSTRUMENTS TGA 2950 Maintenance and Diagnostics 5 24 ...
Page 142: ...Appendix B B 4 TA INSTRUMENTS TGA 2950 ...
Page 152: ...Appendix B B 14 TA INSTRUMENTS TGA 2950 Figure B 2 Figure B 3 ...
Page 153: ...TA INSTRUMENTS TGA 2950 B 15 Hi ResTM Option Figure B 4 Figure B 5 ...
Page 169: ...TA INSTRUMENTS TGA 2950 B 31 Hi ResTM Option Figure B 7 Figure B 8 ...
Page 188: ...Appendix B B 50 TA INSTRUMENTS TGA 2950 Figure B 11 Sensitivity Setting Too High ...
Page 205: ...TA INSTRUMENTS TGA 2950 B 67 Hi ResTM Option Figure B 16 Figure B 17 ...
Page 211: ...TA INSTRUMENTS TGA 2950 B 73 Hi ResTM Option Figure B 22 Figure B 23 ...
Page 212: ...Appendix B B 74 TA INSTRUMENTS TGA 2950 Figure B 24 Figure B 25 ...
Page 214: ...Appendix B B 76 TA INSTRUMENTS TGA 2950 ...
Page 216: ...Appendix C TA INSTRUMENTS TGA 2950 C 2 ...
Page 218: ...Appendix C TA INSTRUMENTS TGA 2950 C 4 Figure C 1 Auto TGA ...
Page 236: ...Appendix D TA INSTRUMENTS TGA 2950 D 2 ...
Page 258: ...Appendix D TA INSTRUMENTS TGA 2950 D 24 ...
Page 264: ...Index TAINSTRUMENTSTGA2950 I 6 ...
