Abstract: Two transversely poled fibers are disclosed which can be wound around a holder with their poling directions being anti-parallel. A coupling exchanges the polarization directions of the modes of the fibers. Thermally and mechanically caused birefringence changes can thereby be substantially cancelled, while electrical field induced birefringence changes can be added, to provide a more robust high voltage measuring device.

Abstract: A pressure sensor is disclosed with at least one pressure sensing element, the pressure induced changes in the optical properties of which are evaluated by illumination with at least one light source. The pressure sensor can include at least two semiconductor-based pressure sensing elements located in individual pressure chambers, which sensing elements are located essentially adjacent to each other. The sensing elements can be irradiated with the same light source, wherein the light transmitted through the sensing elements is detected using at least two corresponding detectors, and wherein the differential pressure in the two pressure chambers is evaluated based on the output of these detectors.

Abstract: An exemplary gas-insulated switchgear device is disclosed which includes a current sensor and a voltage sensor located at a partition insulator. The current sensor can include a magneto-optical fiber on a flexible carrier strip and can be manufactured separately for being easily mounted to an assembled switchgear device. The current sensor can include an electro-optical fiber extending radially into the partition insulator and whose ends are embedded in recesses in the bus bar as well as in the metal embracing of the partition insulator for accurately integrating the voltage.

Abstract: An exemplary gas-insulated switchgear device is disclosed which includes a current sensor and a voltage sensor located at a partition insulator. The current sensor can include a magneto-optical fiber on a flexible carrier strip and can be manufactured separately for being easily mounted to an assembled switchgear device. The current sensor can include an electro-optical fiber extending radially into the partition insulator and whose ends are embedded in recesses in the bus bar as well as in the metal embracing of the partition insulator for accurately integrating the voltage.

Abstract: A pressure sensor is disclosed wherein pressure induced changes in birefringent properties of an optical sensing element are read out by transmission of at least one light beam. The pressure sensor can include at least one single-material transparent body which is subjected to at least two different pressures (p1, p2) in at least two different regions via at least two pressure chambers. The transparent body can transmit by a parallel or minimally divergent light beam without total reflection in the body such that the pressure-induced birefringence and a corresponding differential phase shift between linear polarisation components of the light beam depends on a difference of the different pressures (p1, p2).

Abstract: Two transversely poled fibers are disclosed which can be wound around a holder with their poling directions being anti-parallel. A coupling exchanges the polarization directions of the modes of the fibers. Thermally and mechanically caused birefringence changes can thereby be substantially cancelled, while electrical field induced birefringence changes can be added, to provide a more robust high voltage measuring device.

Abstract: To measure a sum of electrical currents in different conductors, light is led in an optical sensing fiber around all the conductors. The sensing fiber can be wound around the conductors in a single loop or in several individual loops. Interspersed polarization maintaining fibers and retarders can be used to transfer the light between individual loops for preventing undesired signals from stray magnetic fields. The method has high accuracy is particularly suited for measuring large currents that sum up to zero.

Abstract: A pressure sensor is disclosed wherein pressure induced changes in birefringent properties of an optical sensing element are read out by transmission of at least one light beam. The pressure sensor can include at least one single-material transparent body which is subjected to at least two different pressures (p1, p2) in at least two different regions via at least two pressure chambers. The transparent body can transmit by a parallel or minimally divergent light beam without total reflection in the body such that the pressure-induced birefringence and a corresponding differential phase shift between linear polarisation components of the light beam depends on a difference of the different pressures (p1, p2).

Abstract: A pressure sensor is disclosed with at least one pressure sensing element, the pressure induced changes in the optical properties of which are evaluated by illumination with at least one light source. The pressure sensor can include at least two semiconductor-based pressure sensing elements located in individual pressure chambers, which sensing elements are located essentially adjacent to each other. The sensing elements can be irradiated with the same light source, wherein the light transmitted through the sensing elements is detected using at least two corresponding detectors, and wherein the differential pressure in the two pressure chambers is evaluated based on the output of these detectors.

Abstract: A simple, multi-spectral flame detector is disclosed. Such a flame detector has an optical imaging system that is adapted to project several images of the flame onto the same camera. The images are from differing spectral regions. The imaging system comprises several lens devices arranged side by side, e.g., the imaging optics comprise several lens devices arranged side by side, such that each lens device is receiving part of the light from the flame. Each lens device projects one image onto one region of the camera. In this configuration, no beam splitters or mirrors are required, such components being expensive and difficult to align.

Abstract: To measure a sum of electrical currents in different conductors, light is led in an optical sensing fiber around all the conductors. The sensing fiber can be wound around the conductors in a single loop or in several individual loops. Interspersed polarization maintaining fibers and retarders can be used to transfer the light between individual loops for preventing undesired signals from stray magnetic fields. The method has high accuracy is particularly suited for measuring large currents that sum up to zero.

Abstract: A fiber-optic sensor head is disclosed for an optical current or magnetic-field sensor which can have an optical fiber which includes a magnetooptically active sensor fiber which is optically connected to at least one polarization-defining element. The sensor fiber can be arranged in a magnetic field to be measured or around a conductor carrying current to be measured and can be in the form of a coil, with the coil defining a coil plane (A) with a surface normal (Ns), and with the at least one polarization-defining element having a marked axis (f). The sensor head can be flexible in the area of the sensor fiber, and an adjustment means can be provided for adjustment of a predeterminable angle ? between the marked axis,(f) and the surface normal (Ns) or for adjustment of predeterminable angles ?, ?? between the marked axes (f) and the surface normal (Ns).

Abstract: A pole of a high- and/or medium-voltage circuit breaker, including an insulating housing, at least one, interruption chamber which is positioned inside the insulating housing and contains at least a moving contact and at least a fixed contact. A device for measuring the electric current flowing through the pole, and a dielectric gas, the particularity of which is the fact that said device for measuring the electric current flowing through the pole includes an optical current sensor arranged within a volume of the pole that is occupied by the dielectric gas.

Abstract: A device for the investigation of liquids, in particular of waste water, includes at least one reaction chamber for receiving the liquid to be investigated as well as liquids for analysis from storage containers. The reaction chamber is disposed in a housing while the storage containers are accommodated within the housing or are set up outside. The housing may be positioned in a freely floating manner within the liquid to be investigated or may be set up outside.