Patent ID: 8058635
Filing Date: 2011-11-15
Classification: G01F,Y10T

Abstract:
1. A device for the continuous optical determination of the fill level of liquids in liquid tanks of vehicles or airplanes, wherein the liquids have at room temperature and a wavelength of 589 nm a refractive index of at least 1.33, comprising: an elongate measurement channel, that can be arranged on or in a liquid tank in such a manner that liquid located in the tank can enter the measurement channel and form a liquid column within the measurement channel, the dimension of which liquid column in the longitudinal direction of the measurement channel depends on the fill level of the liquid within the liquid tank, a light emitting means that is arranged such that light emitted by the light emitting means can be guided into the measurement channel and pass through it in the longitudinal direction in such a manner that the light passes at least partly through the liquid column located in operation within the measurement channel, and wherein the light emitting means can generate light of a predetermined wavelength or from a predetermined wavelength range, and a detector arrangement that is arranged such that light emitted by the light emitting means into the measurement channel is incident on the detector arrangement after passing through at least a part of the liquid column, wherein the wall of the measurement channel is constructed such that, in operation, the reflection coefficient at the wall in the region of the liquid column for light of the predetermined wavelength or from the predetermined wavelength range is at least 70%, at least for angles of incidence up to a predetermined critical angle.