Abstract: The present invention relates to a device and to a method for detecting at least the presence of gas hydrate crystals (10) formed by a fluid. The device according to the invention comprises: a polychromatic light source (2) likely to emit a radiation (20) at least in the visible spectrum; a body (3, 3?, 3?) comprising a reflecting surface (4) of predefined color in contact with the fluid; means for measuring a light intensity (5) as a function of wavelength, so arranged as to detect a radiation re-emitted in a non-specular manner (21) by reflecting surface (4) when it is illuminated by polychromatic light source (2); means for detecting at least the presence of hydrate crystals (10) from the light intensity measured as a function of wavelength and of at least one predefined threshold.

Abstract: The present invention is a method for measuring the deformation of a subsea pipeline (1), wherein an electromagnetic wave is emitted towards subsea pipeline (1), the electromagnetic wave being reflected by a metal layer (2) of subsea pipeline (1) and the reflected electromagnetic wave being analysed to deduce the deformation of subsea pipeline (1).

Abstract: The invention relates to a device and to a method for separating two immiscible fluids (2, 3), wherein a three-phase system is formed with a Winsor III type bicontinuous phase (4) so as to phagocytize the dispersed droplets and to produce a droplet-free liquid (2).

Abstract: The present invention relates to a method for detecting the presence of gas hydrates and/or ice in a medium. The method comprises at least the following steps: measuring at least at one measurement point in said medium two characteristic values of Raman spectra corresponding to two distinct vibration modes of the OH bonds of water, and determining the ratio ? of said two characteristic values, determining the temperature T in said medium at said measurement point of said spectra, comparing ratio ? with a value ?0 corresponding to a predetermined threshold of formation of said crystals for said temperature T, and determining the presence or not of hydrate and/or ice crystals from said comparison.

Abstract: The device for detecting the presence of gas hydrates and/or ice according to the invention comprises at least: a laser source, at least two band-pass filters, at least one APD detector, at least one means for measuring the temperature at the measurement point, and means for analysing the presence or not of hydrates and/or ice at the measurement point.

Abstract: The present invention relates to a method for detecting the presence of gas hydrates and/or ice in a medium. The method comprises at least the following steps: measuring at least at one measurement point in said medium two characteristic values of Raman spectra corresponding to two distinct vibration modes of the OH bonds of water, and determining the ratio ? of said two characteristic values, determining the temperature T in said medium at said measurement point of said spectra, comparing ratio ? with a value T0 corresponding to a predetermined threshold of formation of said crystals for said temperature T, and determining the presence or not of hydrate and/or ice crystals from said comparison.

Abstract: The device for detecting the presence of gas hydrates and/or ice according to the invention comprises at least: a laser source, at least two band-pass filters, at least one APD detector, at least one means for measuring the temperature at the measurement point, and means for analysing the presence or not of hydrates and/or ice at the measurement point.

Abstract: The present invention is a device for measuring the intensity of the light scattered by a thin film of a colloidal medium, comprising a monochromatic light source, a convergent optical system focusing the source onto the thin film to be analyzed comprising a dioptric element with one of the faces thereof constituting a first wall defining the thin film, at least one photosensitive detector producing a signal representing light scattered or backscattered by the thin film and means for processing the signal. A second wall of the device has a plane surface at the end of a rod.

Abstract: The present invention is a device for measuring the intensity of the light scattered by a thin film of a colloidal medium, comprising a monochromatic light source, a convergent optical system focusing the source onto the thin film to be analyzed comprising a dioptric element with one of the faces thereof constituting a first wall defining the thin film, at least one photosensitive detector producing a signal representing light scattered or backscattered by the thin film and means for processing the signal. A second wall of the device has a plane surface at the end of a rod.

Abstract: The invention relates to a refractometer and to a refractive index measuring method. The invention directs an incident light ray onto an interface of a medium of known refractive index and of the medium studied, then measuring the intensity of the reflected light ray. The ratio between the intensity of the incident ray and the intensity of the reflected ray allows the refractive index of the medium studied to be calculated by means of Fresnel's formulas.

Abstract: The invention relates to a device for detecting the corrosion induced by a medium on a structure. The device comprises a chamber (5) closed by a closing disc (4) made of such a material that the disc becomes permeable to the medium once corroded by the medium, and means for measuring the refractive index of the medium present in the chamber. According to a preferred embodiment, an optical fiber is used to measure the refractive index variation.

Abstract: The invention relates to a device for detecting the corrosion induced by a medium on a structure. The device comprises a chamber (5) closed by a closing disc (4) made of such a material that the disc becomes permeable to the medium once corroded by the medium, and means for measuring the refractive index of the medium present in the chamber. According to a preferred embodiment, an optical fiber is used to measure the refractive index variation.

Abstract: The invention relates to a refractometer and to a method of measuring the refractive index of a medium. An incident light ray is directed onto an interface consisting of a medium of known refractive index and of the medium being studied. Then the intensity of the reflected light ray is measured. The incident and reflected light rays are propagated in an optical fiber section. The ratio between the intensity of the incident ray and the intensity of the reflected ray allows the refractive index of the medium studied to be calculated by means of Fresnel's formulas.

Abstract: The invention relates to a refractometer and to a refractive index measuring method. The invention consists in directing an incident light ray onto an interface consisting of a medium of known refractive index and of the medium studied, then in measuring the intensity of the reflected light ray. The ratio between the intensity of the incident ray and the intensity of the reflected ray allows the refractive index of the medium studied to be calculated by means of Fresnel's formulas.

Abstract: The invention relates to a refractometer and to a method of measuring the refractive index of a medium. An incident light ray is directed onto an interface consisting of a medium of known refractive index and of the medium studied, then the intensity of the reflected light ray is measured. The incident and reflected light rays are propagated in an optical fiber section. The ratio between the intensity of the incident ray and the intensity of the reflected ray allows the refractive index of the medium studied to be calculated by means of Fresnel's formulas.

Abstract: The present invention relates to a device for measuring the luminous intensity scattered by thin films of colloidal media. It is more particularly intended for submicron grain-size analysis by photon correlation, and comprises a device for measuring the luminous intensity scattered by thin films (16) of colloidal media. The invention includes a monochromatic luminous source (2); a converging optical system (4) focusing the source on the thin film to be analyzed; at least one photosensitive detector (5; 5'; 5"; 5'") detecting the light scattered or backscattered by the thin film; and a system (60, 70) for processing the signal coming from photodetector(s) (5).

Abstract: The present invention relates to a method and to a device for testing a partly conductive medium to determine a characteristic thereof. A signal generator generates a periodic excitation signal in a resonant circuit, including a coil which produces a magnetic field, which is coupled to the partially conductive medium. Eddy currents induced in the partially conductive medium cause the current flowing in the resonant circuit to vary. The amplitude of the envelope of the current flowing in the resonant circuit is measured and processed to determine the characteristic of the medium.

Abstract: The invention relates to the measurement of the difference between refractive indexes of two media, traversed by a light beam the beams produce an interference figure consisting of fringes having a displacement which is measured.According to the invention, the displacement of the fringes of the interference figure is detected with a photosensitive device and a phase modulation is performed on at least one of the beams and the modulation is controlled in order to obtain a movement of the fringes of the interference figure.

Abstract: The present invention relates to a system for generating the same instantaneous pressure between two tanks filled each with a given medium, the first tank including at least one inlet channel and at least one outlet channel for the given medium, the second tank including at least one outlet channel, and means for opening and for closing said channels. The system according to the invention further includes at least one linking capillary between each tank, intended notably for transmitting instantaneously a pressure variation from the first tank towards the second tank.