Abstract: This invention provides a device for measuring precipitation by means of radar, comprising an antenna adapted to transmit and receive radar waves and a dielectric lens, the antenna being oriented to the dielectric lens such that radar waves radiated from the antenna pass through the dielectric lens. Furthermore, it is provided a method of determining a velocity of raindrops by radar, comprising the steps of: radiating a radar signal by means of an antenna, receiving a reflected radar signal by said antenna and determining the velocity of the raindrops based on the received reflected radar signal wherein a dielectric lens is disposed in front of the antenna such that the radiated radar signal passes through the dielectric lens.

Abstract: This invention provides a device for measuring precipitation by means of radar, comprising an antenna adapted to transmit and receive radar waves and a dielectric lens, the antenna being oriented to the dielectric lens such that radar waves radiated from the antenna pass through the dielectric lens. Furthermore, it is provided a method of determining a velocity of raindrops by radar, comprising the steps of: radiating a radar signal by means of an antenna, receiving a reflected radar signal by said antenna and determining the velocity of the raindrops based on the received reflected radar signal wherein a dielectric lens is disposed in front of the antenna such that the radiated radar signal passes through the dielectric lens.

Abstract: A vehicle headlight comprising: a lighting unit, a reflector and a headlight glass; a device for determining road conditions, said device being provided in the interior of the vehicle headlight behind the headlight glass and comprising: an infrared transmitter configured for emitting light at predetermined wavelengths through the headlight glass onto a road surface; a detection unit configured for detecting the light emitted by the infrared transmitter and reflected by the road surface through the headlight glass; a processing unit configured for determining surface parameters of the road surface on the basis of the light detected by the detection unit.

Abstract: A method and device for determining the freezing temperature of an ice-water mixture on a road surface. Reference measurements of ice-to-water ratios in dependence on road temperatures for different salt contents of reference ice-water mixtures are provided to the device. The thickness of a water layer on the road surface is detected and the thickness of an ice layer of the road surface is detected by the device and method. From the detected thickness of the water layer and the detected thickness of the ice layer, an ice-to-water ratio of the ice-water mixture is determined. The temperature of the road surface is also detected. The freezing temperature of the ice-water mixture is determined by the device and method from the determined ice-to-water ratio and the detected temperature by means of the provided reference measurements.

Abstract: A method and device for determining the freezing temperature of an ice-water mixture on a road surface. Reference measurements of ice-to-water ratios in dependence on road temperatures for different salt contents of reference ice-water mixtures are provided to the device. The thickness of a water layer on the road surface is detected and the thickness of an ice layer of the road surface is detected by the device and method. From the detected thickness of the water layer and the detected thickness of the ice layer, an ice-to-water ratio of the ice-water mixture is determined. The temperature of the road surface is also detected. The freezing temperature of the ice-water mixture is determined by the device and method from the determined ice-to-water ratio and the detected temperature by means of the provided reference measurements.

Abstract: A control system is described for the electric fuel pump of an internal combustion engine, with a sensor for the speed of a shaft of the engine and with a logic circuit for providing a shut off signal for the pump, depending on the speed detected, where the signal of a further sensor (14) for the speed is supplied to the a logic circuit (16, 17), and where shut off then takes place only when both speed signals deviate from a specified range. In this way, it is ensured that the vehicle remains drivable if one of the two sensors (13) or (14) fails.