Laser Flash Analysis / LFA 457 MicroFlash
A Laser-Flash-Apparatus (LFA) is able to measure the thermal diffusivity D of a sample in a wide temperature range without time-consuming sample preparation steps. The technique uses a short laser pulse, which is absorbed at the front surface of the sample. The temperature of the rear surface of the sample is recorded as a function of time. From the evolution of the temperature signal, the thermal diffusivity D can be determined. Furthermore, by measuring a standard sample simultaneously, the specific heat Cp can be obtained, which is crucial for the determination of the thermal conductivity κ=ρDCp, where ρ is the sample density.
Our laboratory offers a LFA 457 MicroFlash (NETZSCH-Gerätebau GmbH). High and a low temperature furnaces are available to cover the temperature range between -100°C and 1100 °C. An automatic sample change allows measurements of three samples at the same time. The software includes various models to determine the diffusivity D. Further, the specific heat can be determined if a standard sample is measured simultaneously. Standard samples are available for the sample holders with a diameter of 6, 8, 10, and 12.7 mm. The software also calculates the thermal conductivity κ if the sample density ρ and the specific heat Cp are known.
|Temperature range||-100 °C…500 °C (low temperature furnace); room temperature…1100 °C (high temperature furnace)|
|Geometry of quadratic samples||6 x 6 mm2, 8 x 8 mm2|
|Geometry of circular samples||Ø6, Ø8, Ø10, Ø12.7 mm|
|Thickness of the samples||0.1 mm…6 mm depending on thermal conductivity|
|Gas atmospheres||He, N2, Ar|
|Measurement range D||0.01 mm2/s … 1000 mm2/s|
|Measurement range κ||0.1 W/(m*K)…2000 W/(m*K)|
|Accuracy of D||±3%|
|Accuracy of Cp||±5%|
|Repeatability of D||±2%|
|Repeatability of Cp||±3%|