a ) and in mostcases the specific heat ( c Various sample holders Integrated
industrial robot system Special sample holders for
various sample geometries
and even for tests on liquids
can be used in the LFA 457. The LFA 457 MicroFlash
LFA 457 MicroFlash
TM - Measurement Principle
Multi-layer systems Using advanced analysis
routines, two- and three
layer systems can be
analyzed, e.g. for the
characterization of coatings
under real application
conditions. High accuracy andrepeatability Measurements on standard
materials prove that the
thermal diffusivity can be
determined within 3%.
The thermal conductivity can
be directly determined
within 5% for most
materials. The NETZSCH LFA 457 and 1000 mm
2 /s (thermalconductivities between 0.1
and 2000 W/(m*K)). MicroFlash
TM is based on thewell-established flash
method.
The measurement principle
is as follows. The front side
of a plane parallel solid
sample is heated by a short
laser pulse. The heat
induced propagates through
the sample and causes a
temperature increase on the
rear surface. This tempera-
ture rise is measured versus
time using an
infrared detector. The thermal
diffusivity ( ρ ) is known, thethermal conductivity ( λ )canbe determined:The key features of theNETZSCH LFA 457 Absolute measurementtechnique The flash method is an
absolute test technique for
thermal diffusivity. No
calibration is required for the
determination of this
thermophysical property.
λ(T)=a(T)c ρ (T)ρ(T) . MicroFlash
TM are as follows: Non-destructive, non-contact test technique Samples can be analyzed
with other analytical
methods after the tests. Broadest measurementrange The technique can be used
for materials with thermal
diffusivities between 0.01 Temperature dependenttests The instrument allows tests
between -125 and 1100C. Fast testing times Tests at one temperature
generally take only a few
seconds. Measurements
over the entire temperature
range can be done within a
few hours.
p )can be ascertained using the
measured signal. If thedensity (
TM comes with an integratedrobot system for tests on up
to three samples at the
same time. Standarized technique The MicroFlash
TM operates inaccordance with national
and international standards
such as ASTM E-1461, DIN
EN 821 and DIN 30905.3