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International audience; A multi-probe sensor for water content analysis, in liquid biofuels, by using reflection and transmission measurements in microwave frequencies range, is proposed in this letter. As preliminary step and for a better understanding, the measurements were carried out with ethanol/water mixtures, which mimic bioethanol applications, at room temperature. In order to study water/alcohol mixtures, each of them was characterized using classical techniques like open ended coaxial probe or reflection/transmission coaxial line, before being tested in multi-probe sensors. At the end, the multiprobe sensor aims to be implemented in-line production in order to perform diagnosis of water in liquid biofuels.

International audience; The determination of the physical properties of pure water, especially the vapor-pressure curve of water, is one of the major issues identified by the Consultative Committee for Thermometry of the International Committee for Weights and Measures (CIPM) to improve the accuracy of the national references in humidity. At the present time the saturation-pressure data, corresponding to ice or liquid-vapor equilibrium, at low temperature are scarce and unreliable. This study presents new measurements of vapor and sublimation pressures of, respectively, water and ice, using a static apparatus. Prior to saturation-pressure measurements, the temperature and pressure sensors of the static apparatus were calibrated against reference gauges in use at the LNE-CETIAT laboratories. The effect of thermal transpiration has been studied. The explored temperature range lies between 250 K and 374 K, and the pressure range between 70 Pa and 10(5) Pa. An automatic data acquisition program was developed to monitor the pressure and temperature. The obtained results have been compared with available literature data. The preliminary uncertainty budget took into account several components: pressure measurements, temperature measurements, and environmental error sources such as thermal transpiration and hydrostatic correction.