NeoTIM measure :
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Measurement methods :
We realize specific autosamplers for high temperature measurement and for fusion / solidification of materials.
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Measurements on any type of materials :
solids, liquid, pasty, aerogels,…
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The majority of thermophysical definition methods that we employ are based around the use of shock sensors. They enable the thermal disruption of the material, the response to this disruption depends on these thermal conditions.
The hot disk is an analyser of thermophysical properties developped by a Swedish company that uses a patented technique of flat source transitory. A sensor formed by a double spiral nickel on an isolating support made out of kapton or mica (according to the measurement temperature) is positioned between 2 samples of the studied material.
The hot disk measures the thermal conductivity and the thermal diffusivity enabling the estimation of the heat capacity.
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The hot wire method enables the estimation of the thermal conductivity of a material from the change in temperature measured by a thermal sensor placed close to a resistant wire. The sensor made of a resistant wire and the thermocouple suported in an isolating kapton support, is positionned between 2 samples of the material to be studied.
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| Hot wire |
The hot ribbon method is particularly useful for the thermal study of isolating materials. The perfectly symetrical sensor is made of 2 rectangular heating resistors stuck together, between which a type K thermocouple measures the differences in temperature. The thermocouple allows the measurement of the rise in temperature at the center of the heating sensor. The thermal conductivity (conductivity <1 W/m/K) as well as the volumic heat can be calculated using the acquired thermogram together with a mathematical model.
The principle of the flash method relies on the transitory analysis of the temperature of the back side of a cylindrical sample initialy isothermic put on a photothermal shock on the front face. This thermal disruption is achieved by flash.
The length of the shock is roughly a millisecond. The rise in temperature is measured on the back side with the aid of a thermocouple with a separated contact. A mathematical model allows the calculation of the thermal diffusiveness of the sample.
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The calorimetric analysis mainly enables the measurement of the material specific heat. 2 models from the SETARAM range are used in the laboratory :
TG-DSC 111 : the TG-DSC 111 allows the simultaneous measurement DSC (variation of thermal flow) and ATG (variation in mass) in the same sample. The sensor of the DSC 111 is composed of 2 thermopilies mounted opposite one another in the middle part of 2 tubes made out of refractory materials. Together it is put in a heating metal block. The melting pot is totally covered by the thermopile, which allows a total measurement of the heat exchange. Measurement up to 800 deg C.
Calvet C80 calorimeter : differential appliances. 2 thermopiles suround respectively a measurement cell in which is placed the sample to be studied and a reference cell containing a thermally inert product. Differencial analysis allows the elimination of all parasitic thermal phenomena that are not linked to the studied reaction and therefore get a very high sensitivity. Available in an isothermal version or programmable between the ambient temperature and 300 deg C, the C80 can detect very weak thermal phenomena.