Dilatometry
yields powerful infomation regarding the thermal expansion
and shrinkage of materials during thermal treatment. On the
other hand interpretation of transitions occurring in the
sample is sometimes difficult, using only thermal expansion
data. The new c-DTA® feature
for the DIL 402 is an additional tool for a more detailed
insight into material behavior. Differential Thermal Analysis
(DTA) is a well-known tool for the characterization of transformation
energetics (exo- and endothermal effects). Calculation of
the c-DTA® signal
on a thermal expansion curve yields information similar to
the DTA method.
c-DTA® calculation
is a mathematical routine based on the temperature measurement
at the sample. Transitions connected with exo- or endothermal
effect, of course, slightly influence the temperature change
during dynamic heating or cooling. By comparing the measured
temperature change of the sample with a theoretical one these
exo- or endothermal effects can be detected. If a calibration
run on a standard sample is carried out prior to the sample
run, this is also considered in the calculation process.
Example:
Floor Tile
The thermal expansion and sintering
of a floor tile during firing can easily be studied using the
DIL 402. The additional c-DTA® feature
allows more detailed insight into the thermal behavior of the
material. The endothermal effect at 118¡C is due to dehydration.
The exothermal peak at 316¡C is due to the burnout of organic
additives. Dehydration of the clays was measured at 581¡C (peak
temperature). The exothermal effect at 917¡C is due to a solid-state
transition in the sample. (The c-DTA®-curve
was calculated stepwise.)
NETZSCH offers
precision thermal analysis instruments including advanced dilatometers (with
a new basic R&D/QC dilatometer),
classical DSC & TGA (with
a new economical DSC), high temperature DSC
to 1650°C for specific heat, very high temperature STA
(TGA-DSC/DTA) to 2400°C (featuring the new STA
409-PC Luxx®), thermal
/ evolved gas analysis with fully-integrated FTIR & MS, plus
high resolution TMA and DMA.
We also feature leading technology for thermal conductivity and diffusivity measurement
as well as refractories testing including HMOR, CIC, and RUL.
