Abstract: A measuring device measures an electrical current and contains a light source for generating a polarized primary light signal for feeding into a Faraday sensor unit, and a detector for detecting a secondary light signal provided by the Faraday sensor unit and polarization-altered in relation to the primary light signal. An optical-electrical compensation element, by which the polarization alteration of the secondary light signal can be compensated via an opposite polarization alteration, and a measurement signal, according to the opposite polarization alteration, for the electrical current can be deduced. A method for measuring an electrical current by use of the measuring device is further disclosed.

Abstract: An arrangement for temperature measurement at high-voltage potential is disclosed. The energy for measuring the temperature of an optical current transformer is provided by a single photodiode. The photodiode is supplied by light emitted by a light source and guided to the photodiode via an optical waveguide.

Abstract: A measuring device measures an electrical current and contains a light source for generating a polarized primary light signal for feeding into a Faraday sensor unit, and a detector for detecting a secondary light signal provided by the Faraday sensor unit and polarization-altered in relation to the primary light signal. An optical-electrical compensation element, by which the polarization alteration of the secondary light signal can be compensated via an opposite polarization alteration, and a measurement signal, according to the opposite polarization alteration, for the electrical current can be deduced. A method for measuring an electrical current by use of the measuring device is further disclosed.

Abstract: A temperature sensor arrangement for gas turbines is provided. The temperature sensor arrangement has a measuring probe. The measuring probe has a bore in which a steel tube is guided so as to be axially movable. The steel tube includes a glass fibre having Bragg grating measurement points for measuring the temperature. Elongate measurement openings enable hot gas to flow through the measuring probe, flowing round the steel tube in the region of the Bragg grating.

Abstract: An arrangement for temperature measurement at high-voltage potential is disclosed. The energy for measuring the temperature of an optical current transformer is provided by a single photodiode. The photodiode is supplied by light emitted by a light source and guided to the photodiode via an optical waveguide.

Abstract: A device for transmitting or receiving a light beam is provided. The device includes an angular adjustment element and a fiber-optic cable which emits light and is connected to the angular adjustment element. The fiber-optic cable ends in the region of the angular adjustment element. The angular adjustment element enables a radiation direction of a light beam of the fiber-optic cable to be fixed, wherein, in at least some of possible radiation directions, the light beam passes through a fixed point which is independent of the radiation direction, wherein the fixed point lies outside the device.

Abstract: A gas turbine with at least one stationary stator blade and at least one rotor blade that can be rotated during operation is provided. The gas turbine has at least one optical waveguide embedded into a first rotor blade. The optical waveguide is oriented such that thermal radiation of a region of the first stator blade can be detected by the optical waveguide. An analyzing device is designed to analyze the thermal radiation and to ascertain the temperature of the region of the first stator blade, the temperature being ascertainable along a path from which the radiation is emitted during the rotation of the first rotor blade.

Abstract: A temperature sensor arrangement for gas turbines is provided. The temperature sensor arrangement has a measuring probe. The measuring probe has a bore in which a steel tube is guided so as to be axially movable. The steel tube includes a glass fibre having Bragg grating measurement points for measuring the temperature. Elongate measurement openings enable hot gas to flow through the measuring probe, flowing round the steel tube in the region of the Bragg grating.

Abstract: A fiber-optic vibration sensor for generators in power stations is disclosed. The sensor includes an optical fiber which has a freestanding end, wherein the freestanding end is caused to oscillate under the influence of vibrations, and the resulting oscillations are detected as a measure for the vibrations. Only the net weight of the optical fiber serves as a centrifugal mass.

Abstract: A regulation system for a compressor comprises a fiber-optic lattice sensor which makes it possible to determine a flow temperature of a fluid to be compressed by means of the compressor. Another aspect of the invention relates to a use of a fiber-optic Bragg lattice sensor as a temperature sensor in a regulation system.

Abstract: A method determines the layer thickness of a TBC coating of at least one blade of a non-positive-displacement machine. To this end, at least one electromagnetic wave is emitted to the surface of the at least one blade, the at least one electromagnetic wave is then at least partially reflected by the at least one blade, and the reflected portion of the at least one electromagnetic wave is received and subsequently processed. In addition, the at least one electromagnetic wave is emitted with a frequency matched to the layer thickness of the TBC coating, and the phase of the at least one electromagnetic wave is compared with the phase of the at least one received electromagnetic wave. The at least one emitted electromagnetic wave undergoes a phase change during reflection and the layer thickness of the TBC coating is determined by the phase comparison.

Abstract: A flowmeter determines the flow direction of a fluid. The flowmeter has a measuring element, around which the fluid flows and which comprises at least one fiber-optic cable and at least two electrical heating elements that lie adjacent to the fiber-optic cable(s) by a respective heat stream emanating from the respective heating element and directed towards at least one fiber-optic cable, the directions of the heat streams being at least proportionately reversed. In addition, the values of the individual heat streams can be influenced to different extents, depending on the flow direction of the fluid. An electromagnetic wave that can be coupled into the fiber-optic cable(s) can also be influenced according to the temperature of the fiber-optic cable(s).

Abstract: For a temperature measurement in areas having electromagnetic fields, shielding devices must be provided. According to the proposed technique, at least one temperature sensor is designed as a fiber-optic sensor having Bragg gratings (FBG), wherein the sensor is arranged in a non-metallic housing that precludes or minimizes expansion effects for the individual FBG sensors. For example, the proposed technique can be used advantageously to measure the temperature distribution in oil sand deposits, for which purpose a suitable measuring arrangement is required.

Abstract: A fiber-optic vibration sensor for generators in power stations is disclosed. The sensor includes an optical fiber which has a freestanding end, wherein the freestanding end is caused to oscillate under the influence of vibrations, and the resulting oscillations are detected as a measure for the vibrations. Only the net weight of the optical fiber serves as a centrifugal mass.

Abstract: A device for determining distance between a rotor blade and a wall of a gas turbine surrounding the rotor blade is provided. A waveguide guides and emits electromagnetic waves of at least one frequency in the direction of the rotor blade through a waveguide opening facing the rotor blade. The electromagnetic waves are injected into the waveguide and reflected portions of the electromagnetic waves are received. An evaluation unit compares the phase of the electromagnetic waves to be injected with the phase of the reflected portions of the electromagnetic waves and determines phase comparison values for every frequency and the distance is determined based on the phase comparison values. The waveguide comprises a sealing element which is configured to be transmissible for the electromagnetic waves of the frequency and which has two opposite surfaces in the direction of guidance of the electromagnetic waves.

Abstract: A pyrometer for gas turbines is provided. Incident thermal radiation is split between a plurality of optical wave guides by a reflection prism and a lens according to regions on the surface of a turbine blade. The pyrometer is built into the wall of the turbine without protruding and enables the simultaneous and parallel measurement of the temperature of a plurality of regions on the surface of the turbine blade when a spectrum of the heat radiation is largely maintained.

Abstract: A device for determining distance between a rotor blade and a wall of a gas turbine surrounding the rotor blade is provided. A waveguide guides and emits electromagnetic waves in the direction of the rotor blade through a waveguide opening facing the rotor blade. The electromagnetic waves are injected into the waveguide and reflected portions of the electromagnetic waves are received. An evaluation unit compares the phase of the electromagnetic waves to be injected with the phase of the reflected portions of the electromagnetic waves and determines phase comparison values for every frequency and the distance is determined based on the phase comparison values. The waveguide includes two waveguide segments made from different materials having temperature stability and damping capacity increasing in the direction from the segment connected to the unit for injecting the waves to the segment having the waveguide opening.

Abstract: An optical device for monitoring a rotatable shaft is disclosed. The optical device has an optical waveguide arranged on the rotatable shaft and an optical sensor. The optical device further has a transmitting unit transmit the light signal, a transfer device to transmit the light signal between the transmitting unit and the optical waveguide and an evaluation unit for determining a physical variable from a light signal coming from the optical sensor and transferred by the transfer device, the evaluation unit being associated with the transmitting unit. The transfer device has an optical ‘multimode’ waveguide associated with a coupling device, the waveguide being associated with the transmitting unit and a further optical ‘multimode’ waveguide, with an associated coupling device associated with the optical waveguide and arranged on the rotatable shaft eccentrically to its axis.

Abstract: A flowmeter determines the flow direction of a fluid. The flowmeter has a measuring element, around which the fluid flows. The measuring element has fiber-optic cable and at least two electrical heating elements that lie adjacent to the fiber-optic cable(s) by which a respective heat stream emanating from the respective heating element and directed towards the fiber-optic cable, the directions of the heat streams being at least proportionately reversed. In addition, depending on the flow direction of the fluid, the individual heat streams are correlated to different extents with the flow direction. An electromagnetic wave that can be coupled into the fiber-optic cable(s) can also be influenced according to the temperature of the fiber-optic cable(s).

Abstract: A device for transmitting or receiving a light beam is provided. The device includes an angular adjustment element and a fiber-optic cable which emits light and is connected to the angular adjustment element. The fiber-optic cable ends in the region of the angular adjustment element. The angular adjustment element enables a radiation direction of a light beam of the fiber-optic cable to be fixed, wherein, in at least some of possible radiation directions, the light beam passes through a fixed point which is independent of the radiation direction, wherein the fixed point lies outside the device.