תיאור
A special version with a pyrometer allows measurements from room temperature to 2800°C.
The thermal conductivity of disk-shaped samples of ceramic, glass, metals, melts and liquids, powders, fibers and multi-layer materials ranging from vacuum insulation panels to diamonds is measured with equal speed and accuracy. The temperature-dependent measured thermal diffusivity value along with the corresponding specific heat (DSC 404 F1Pegasus®) and density (DIL 402 C) data are used to calculate the thermal conductivity.
The laser power, pulse width, gas and vacuum are variable over a wide range, making it possible to set the optimum measurement conditions for the very different sample properties.
The LFA 427 is the most powerful and versatile LFA system for research and development as well as all applications involving characterization of standard and high-performance materials in automobile manufacturing, aeronautics, astronautics and energy technology.
Key Technical Data
(subject to change)
Temperature range:
-120°C to 400°C, RT to 1300°C, RT to 1575°C, RT to 2000°C, RT to 2800°C
(5 furnace types)
Heating- and cooling rates:
0.01 K/min to 50 K/min
(dependent on furnace)
Laser power
25 J/pulse,
(adjustable power and pulse duration)
Contactless measurement of temperature rise
with IR detector
Measuring range:
0.01 mm2/s to 1000 mm2/s
(thermal diffusivity)
Measuring range:
0.1 W/mK to 2000 W/mK
(thermal conductivity)
Sample dimensions:
6 mm to 12.7 mm diameter (20 mm special version), 10×10 mm square
0.1 mm to 6 mm thickness
Sample holder:
Al2O3, graphite
Liquid metal holder:
sapphire
Sample holder for liquids:
platinum
Atmospheres:
inert, oxidizing, reducing, static, dynamic
High vacuum-tight assembly
up to 10-5 mbar
LFA features:
- Accurate pulse length correction, pulse mapping
- Heat-loss corrections, all literature models are integrated
- Non-linear regression for Cowan fit
- Improved Cape-Lehmann model through consideration of multi-dimensional heat loss and non-linear regression
- Radiation correction for semi-transparent samples
- 2- or 3-layers systems: analysis by means of non-linear regression and consideration of heat loss
- Determination of contact resistance in multi-layer systems
- Model wizard for selecting the optimum evaluation model
- Determination of specific heat by means of a comparative method and standard samples
- Integrated databank
Accessories
- The LFA 427 is equipped with a cooling thermostat to guarantee the greatest temperature and long-term stability.
- Various vacuum pumps, including turbomolecular pumps, enable measurements at reduced pressure, in high vacuum or in pure, oxygen-free atmospheres.
- Flow meter for purge gas
- Sample holders and caps made of aluminum, SiC and graphite for standard sample dimensions
- A number of sample holders made of alumina, platinum, aluminum and sapphire are available in various sizes for liquid samples, metal melts, slags and fibers.
- Reference samples for thermal diffusivity
- Reference samples for specific heat
