Abstract: Aspects of the invention relate to a semiconductor chip comprising a substrate and a stack arranged on the substrate. The stack comprises one or more insulating layers and one or more metal layers. The chip comprises a sensor device arranged in a sensor area (SA) of the semiconductor chip and processing circuitry arranged in a processing area (PA) of the semiconductor chip. The chip further comprises connection circuitry configured to provide an electrical connection between the sensor device and the processing circuitry. A first seal ring structure is arranged between an outer edge (ED) of the chip and an inner area (IA) of the chip. The inner area (IA) of the chip encompasses the sensor area (SA) and the processing area (PA). A second seal ring structure is arranged between the sensor area (SA) and the processing area (PA) and configured to constrain an infiltration of contaminants from the sensor area (SA) to the processing area (PA).

Abstract: Sensor structure (16) is provided for online monitoring of levels of Furans in oil of a transformer tank. The sensor structure includes a UV light source (26), a filter (30) permitting only UV light of a certain wavelength range to pass, a window (32) permitting the filtered UV light to passes there-through and a UV light detector (36) to receive UV light that passes through the window. When the sensor structure is mounted to the transformer tank that is online so that the window is exposed to oil, and Furans in the oil are being monitored, the Furans will absorb UV light, creating a difference in UV light received by the light detector when compared to the UV light received by the light detector when the monitored oil has no Furans therein. The output signal of the light detector is substantially proportional to a total of Furans in the monitored oil.

Abstract: A fiber-optic current sensor includes a measuring unit having a light source and a light detector, and a sensing head having a sensing fiber wound around a conductor and a retarder connected to the sensing fiber. The scale factor as a function of current of the fiber-optic current sensor is described by the product of two scaling functions fe? and fs? for the measuring unit and the sensing head, respectively. The data describing the scaling functions fe?, fs? is stored in a memory of the measuring unit, while the data describing the scaling function fs? is also stored in a memory of the sensing head. Providing two such memory devices allows to store the scaling functions fe? and fs? separately, thereby turning the control unit as well as the sensor head into easily replaceable modules.

Abstract: Sensor structure (16) is provided for online monitoring of levels of Furans in oil of a transformer tank. The sensor structure includes a UV light source (26), a filter (30) permitting only UV light of a certain wavelength range to pass, a window (32) permitting the filtered UV light to passes there-through and a UV light detector (36) to receive UV light that passes through the window. When the sensor structure is mounted to the transformer tank that is online so that the window is exposed to oil, and Furans in the oil are being monitored, the Furans will absorb UV light, creating a difference in UV light received by the light detector when compared to the UV light received by the light de tector when the monitored oil has no Furans therein. The output signal of the light detector is substantially proportional to a total of Furans in the monitored oil.

Abstract: A fiber optic current or magnetic field sensor uses a sensing fiber in a coil for measuring a current or a magnetic field and has a retarder for converting between linearly polarized light and elliptically polarized light. The retardation of the retarder, its temperature dependence as well as its azimuth angle in respect to the plane of the fiber coil are optimized in dependence of the birefringence in the sensing fiber in order to minimize the influence of temperature variations and manufacturing tolerances on the overall scale factor of the sensor.

Abstract: A method is provided for tuning the fiber optic retarder of a fiber optic current sensor towards a desired temperature dependence, the sensing fiber is exposed to a magnetic field or corresponding electric current and the sensor signal as well as the signal's dependence on the retarder temperature are measured. From this initial sensor signal and its temperature dependence, a target sensor signal can be determined, at which the dependence on the retarder temperature equals a desired value. Then, the retarder is thermally treated until the sensor signal reaches the target value. The method obviates the need for repetitively measuring the temperature dependence during the tuning process.

Abstract: A fiber-optic current sensor includes a measuring unit having a light source and a light detector, and a sensing head having a sensing fiber wound around a conductor and a retarder connected to the sensing fiber. The scale factor as a function of current of the fiber-optic current sensor is described by the product of two scaling functions fe? and fs? for the measuring unit and the sensing head, respectively. The data describing the scaling functions fe?, fs? is stored in a memory of the measuring unit, while the data describing the scaling function fs? is also stored in a memory of the sensing head. Providing two such memory devices allows to store the scaling functions fe? and fs? separately, thereby turning the control unit as well as the sensor head into easily replaceable modules.

Abstract: A method is provided for tuning the fiber optic retarder of a fiber optic current sensor towards a desired temperature dependence, the sensing fiber is exposed to a magnetic field or corresponding electric current and the sensor signal as well as the signal's dependence on the retarder temperature are measured. From this initial sensor signal and its temperature dependence, a target sensor signal can be determined, at which the dependence on the retarder temperature equals a desired value. Then, the retarder is thermally treated until the sensor signal reaches the target value. The method obviates the need for repetitively measuring the temperature dependence during the tuning process.

Abstract: A fiber optic current or magnetic field sensor uses a sensing fiber in a coil for measuring a current or a magnetic field and has a retarder for converting between linearly polarized light and elliptically polarized light. The retardation of the retarder; its temperature dependence as well as its azimuth angle in respect to the plane of the fiber coil are optimized in dependence of the birefringence in the sensing fiber in order to minimize the influence of temperature variations and manufacturing tolerances on the overall scale factor of the sensor.