Abstract: A method and apparatus for determining the location of a phase boundary such as a fill level, in a vessel. The method includes: providing at least one source of radiation capable of emitting radiation through a portion of the interior of the vessel; providing a plurality of radiation detectors, each detector being capable of detecting, within a part of the measurement range, radiation emitted by the source; and providing a data processing unit for calculation of the position of the phase boundary from the amount of radiation detected by the detectors, wherein the data processing unit calculates the position of the phase boundary from the amount of radiation detected by the detectors by: (i) in a first step, determining within which detector stage the phase boundary is located; and then (ii) in a second step, determining the position of the phase boundary within the detector stage determined in (i).

Abstract: A method and apparatus for determining the location of a phase boundary such as a fill level, in a vessel. The method includes: providing at least one source of radiation capable of emitting radiation through a portion of the interior of the vessel; providing a plurality of radiation detectors, each detector being capable of detecting, within a part of the measurement range, radiation emitted by the source; and providing a data processing unit for calculation of the position of the phase boundary from the amount of radiation detected by the detectors, wherein the data processing unit calculates the position of the phase boundary from the amount of radiation detected by the detectors by: (i) in a first step, determining within which detector stage the phase boundary is located; and then (ii) in a second step, determining the position of the phase boundary within the detector stage determined in (i).

Abstract: An apparatus for communicating video frames from a source having a video input means to a destination having a visual display unit during the course of a telephone conversation. A first user can use a first computer communication means to make a first connection to a service provider. The service provider or first user then initiates a telephone call from the first to the second telephone via the service provider and the first and second communication paths. A second user can then use the second computer communication means to make a second connection to the service provider. Caller-id data is communicated between each of the first and second users and the service provider so that the service provider can correlate both the call and the first and second connections with each other. At least one video image is uploaded from the video input means to the service provider, and then downloaded to one of the computers.