The aim of this work is to present an infrared calorimeter for the measurement of the kinetics and the enthalpy of high exothermic chemical reactions. The main idea is to use a millifluidic chip where the channel acts as a chemical reactor. An infrared camera is used to deduce the heat flux produced by the chemical reaction from the processing of temperature fields. Due to the size of the microchannel, a small volume of reagents (ml) is used. As the chemical reagents are injected by a syringe pump, continuous experiments are performed with a very good control of the reagents mixing. A specific injection system enables to perform two flow configurations: co-flow and droplets. Thanks to the thermal isoperibolic conditions, the chemical reaction can be easily characterized with a previous specific calibration. Here, the gradual mixing by species diffusion and the enthalpy of a strong acid base reaction are monitored in co - flow configuration

International audienceRecent advances for the measurement of TeraHertz (THz) radiation by using original IR temperature flux sensors are presented. The bolometer principle is used for designing simple thermal converters for THz radiations (measurement of the temperature increase of a sensitive absorber). Most of these sensors are efficient, sensitive and fast enough for quantitative measurement of THz source power as well as for 2D and 3D THz imaging. By combining optical and thermal technologies, we extend and adapt the use of thermal sensors to large THz wavelength till 3 mm (0.1 THz). A large variety of mono- or arrayed- thermal sensors is used and optimized for real-time room temperature THz imaging using adapted IR focal-plane microbolometers array (FPMA) camera. Optimisation and adaptation of such FPMA is discussed and a new arrayed prototype device of THz-Thermal Converter, "TTC", for full-field real-time THz imaging is presented. This small size, low cost and efficient prototype design is discussed from the thermal point of view and is characterized using a compact powerful THz source. Their sensitivity is evaluated and the obtained 2D and 3D images clearly illustrates the high potential of this new kind of THz camera. Finally, it is shown that non-arrayed extended plane TTCs (EMIR sensitivescreens) coupled to FPA cameras produce THz images free of diffraction phenomena

In this paper, the problem of the quantitative characterization of thermal resistance fields in a multilayer sample is addressed by using the classical front face flash method as the thermal excitation and infrared thermography (IRT) as the monitoring sensor. In this challenging problem, the complete inverse processing of a multilayer analytical model is difficult due to the lack of sensitivity of some parameters (layer thickness, depth of thermal resistance, etc.) and the expansive computational iterative processing. For these reasons, the proposed strategy is to use a simple multilayer problem where only one resistive layer is estimated. Moreover, to simplify the inverse processing often based on iterative methods, an asymptotic development method is proposed here. Regarding the thermal signal reconstruction (TSR) methods, the drawback of these methods is the inability to be quantitative. To overcome this problem, the method incorporates a calibration process originating from the complete analytical quadrupole solution to the thermal problem. This analytical knowledge allows self-calibration of the asymptotic method. From this calibration, the quantitative thermal resistance field of a sample can be retrieved with a reasonable accuracy lower than 5%.

The main objective of this work is to present a method for measuring the specific heat of single metallic, carbon, and ceramic fibers at very high temperature. The difficulty of the measurement is due to the microscale of the fiber (≈10μm) and the important range of temperature (700–2700K). An experimental device, a modelization of the thermal behavior, and an analytic model have been developed. A discussion on the measurement accuracy yields a global uncertainty lower than 10%. The characterization of a tungsten filament with thermal properties identical to those of the bulk allows the validation of the device and the thermal estimation method. Finally, measurements on carbon and ceramic fibers have been done at very high temperature.