NETZSCH LFA 447 Nanoflash, Operating Instructions Manual

Page: 38 / 89

System Components
LFA 447
TM
01/09 J:\LFA447\CHAPTER3.DOC
12
Determination of the liquid level in the crucible
h
total
h
sample
h
lid
h
crucible
For measurements, the 3 layer model for determination of the thermal diffusivity of
the liquid must be used. This means that the bottom thickness of the crucible h
crucible
,
the liquid level h
sample
and the thickness of the cover bottom h
lid
must be precisely
known. The thickness of the crucible bottom h
crucible
and the lid bottom h
lid
can be
measured with a micrometer screw. The liquid level h
sample
is the difference between
the total height of the sample holder h
total
and the thickness of the crucible bottom
h
crucible
plus the cover bottom h
lid
:
h
sample
= h
total
- h
lid
- h
crucible
After the measurement, e.g. polymer melting, the total height of the sample holder
should be remeasured. If the total height of the sample holder h
total
has risen, the
liquid level has changed during the measurement. For an ideal measurement, the
liquid level must be constant during the measurement.