A method and a device for generating a signal which indicates the imminent formation of slipperiness on a roadway (2) before this arises on the roadway, wherein radiation reflected from the roadway, or from a point adjacent to the roadway, is evaluated, which radiation emanates from at least one reference surface (11) arranged in or on the roadway or the adjacent point, which reference surface is formed by a material different from the roadway covering material. The reference surface is selected from a material on which slipperiness is formed earlier than on the road surface material. The signal (13) is emitted when the evaluation shows that slipperiness has formed on the reference surface (11).

The present invention relates, but without limitation, to a system and method for detecting the formation of ice on a surface of a body (1) on which an air stream impinges. Said system comprises: a first and a second temperature detectors (2, 5) with different thermal inertia; and an electro-optic module (10) connected to both detectors (2, 5). Thus, by calculating the different responses of the detectors (2, 5) it is possible to detect the ice formation on a body (1), and more advantageously, the almost instantaneously freezing of supercooled water on a body (1). The present invention can be applied to aircrafts, wind turbines or to electrical power transmission lines.

The present invention relates, but without limitation, to a system and method for detecting the formation of ice on a surface of a body (1) on which an air stream impinges. Said system comprises: a first and a second temperature detectors (2, 5) with different thermal inertia; and an electro-optic module (10) connected to both detectors (2, 5). Thus, by calculating the different responses of the detectors (2, 5) it is possible to detect the ice formation on a body (1), and more advantageously, the almost instantaneously freezing of supercooled water on a body (1). The present invention can be applied to aircrafts, wind turbines or to electrical power transmission lines.

An ice detection system for an aircraft surface includes a sensor assembly comprising a plurality of temperature sensitive elements configured to be arranged at respective points on the aircraft surface, a control unit arranged to receive signals indicative of a temperature sensed by each of the temperature sensitive elements, a signal conducting bus to transmit the signals from the temperature sensitive elements to the control unit, and means for providing power to the sensor assembly, wherein the sensor assembly further comprises a multiplexer arranged to multiplex the signals from the plurality of temperature sensitive elements into a single signal for transmission on the signal conducting bus to the control unit.

An ice detection system for an aircraft surface includes a sensor assembly comprising a plurality of temperature sensitive elements configured to be arranged at respective points on the aircraft surface, a control unit arranged to receive signals indicative of a temperature sensed by each of the temperature sensitive elements, a signal conducting bus to transmit the signals from the temperature sensitive elements to the control unit, and means for providing power to the sensor assembly, wherein the sensor assembly further comprises a multiplexer arranged to multiplex the signals from the plurality of temperature sensitive elements into a single signal for transmission on the signal conducting bus to the control unit.

An electric field sensor includes an insulating substrate, a plurality of electrodes, an insulator, a plurality vias, and a ground ring. The electrodes are disposed on the substrate. The insulator is disposed over the electrodes. The vias are coupled to the electrodes and extend through the substrate at a right angle to the electrodes. The ground ring is disposed around the electrodes and the vias and is configured to attenuate a sensitivity of the sensor to electric fields outwards of the ground ring.

An electric field sensor includes an insulating substrate, a plurality of electrodes, an insulator, a plurality vias, and a ground ring. The electrodes are disposed on the substrate. The insulator is disposed over the electrodes. The vias are coupled to the electrodes and extend through the substrate at a right angle to the electrodes. The ground ring is disposed around the electrodes and the vias and is configured to attenuate a sensitivity of the sensor to electric fields outwards of the ground ring.

In an embodiment, an optical ice detection method is provided. The method includes contacting a multilayer structure with water under conditions effective to form ice, the multilayer structure comprising an optically transparent or semi-transparent material disposed over at least a portion of a material probe. The method further includes performing Raman spectroscopy on one or more of the material probe, water, or ice to obtain Raman spectra, detecting a shift in the Raman spectra, and calculating ice-induced strain in the material probe. Apparatus for optically detecting ice are also provided.

In an embodiment, an optical ice detection method is provided. The method includes contacting a multilayer structure with water under conditions effective to form ice, the multilayer structure comprising an optically transparent or semi-transparent material disposed over at least a portion of a material probe. The method further includes performing Raman spectroscopy on one or more of the material probe, water, or ice to obtain Raman spectra, detecting a shift in the Raman spectra, and calculating ice-induced strain in the material probe. Apparatus for optically detecting ice are also provided.

A method of monitoring for the in-flight accretion of matter involves an electric field sensor applying a time-varying electric field to an engine surface of an aircraft while the aircraft is in flight. The electric field sensor is thermally-coupled and thermally-matched to the engine surface. A sensor monitor receives, in substantially real-time from the electric field sensor, at least one measurement set that includes a measurement of a phase and a magnitude of a current detected by the electric field sensor and resulting from the time-varying electric field. The sensor monitor generates an assessment, in substantially real-time, of an instantaneous accumulation of matter on the engine surface from the at least one measurement set. The sensor monitor activates an alarm upon the assessment indicating an accumulation of matter on the engine surface.