Abstract: An arrangement for obtaining electrical state information related to an electrical power cable comprising at least one current sensor, at least one electrical-mechanical transducer arranged in order to receive a current sensor signal based driving signal and adapted to generate a mechanical response at a response surface based on the driving signal, a distributed acoustic sensing equipment, comprising at least one first optical fibre, and a processing portion adapted to process detected first Rayleigh backscattered light in order to at least determine the value of a current related to the power cable.

Abstract: It is described an arrangement for obtaining electrical state information related to an electrical power cable, the arrangement comprising: at least one current sensor arrangeable at at least one measurement location and adapted to generate a current sensor signal indicative of a value of an electrical current related to the electrical power cable; at least one electrical-mechanical transducer arranged in order to receive a current sensor signal based driving signal and adapted to generate a mechanical response at a response surface based on the driving signal; a distributed acoustic sensing equipment, comprising: at least one first optical fibre having a first end and a second end, a contact portion of the first optical fibre between the first end and the second end being mechanically in contact with the response surface; an interrogation system adapted to generate temporally successively optical pulses and coupleable to the first end of the first optical fibre in order to inject the optical pulses into the

Abstract: A system and technique for obtaining two or more distributed measurements from an optical sensing fiber deployed along a desired measuring path are disclosed. Interrogating probes from two or more different distributed measuring systems are combined and launched into the sensing fiber. Backscattered light generated in response to the combined interrogating probes is separated into portions and each portion is provided to a respective distributed measuring instrument. In this manner, distributed measurements corresponding to different parameters of interest, such as temperature and pressure, along the measuring path can be measured simultaneously using the same sensing fiber.

Abstract: A technique facilitates monitoring of flow conditions with respect to flow through a tubing. A distributed sensor is routed along an interior of the tubing to monitor flow conditions. For example, the distributed sensor may be routed over a length of the tubing having a lateral opening. Fluid is flowed along the distributed sensor and within the interior of the tubing. The distributed sensor is operated to measure strain which results from flow of the fluid along the distributed sensor. The strain may then be evaluated to determine a change in a flow condition, such as a change in a flow condition related to the lateral opening.

Abstract: A system and technique for obtaining two or more distributed measurements from an optical sensing fiber deployed along a desired measuring path are disclosed. Interrogating probes from two or more different distributed measuring systems are combined and launched into the sensing fiber. Backscattered light generated in response to the combined interrogating probes is separated into portions and each portion is provided to a respective distributed measuring instrument. In this manner, distributed measurements corresponding to different parameters of interest, such as temperature and pressure, along the measuring path can be measured simultaneously using the same sensing fiber.

Abstract: An optical fiber sensor system and method for monitoring a condition of a linear structure such as a pipeline is provided which is capable of providing continuous monitoring in the event of a break in the sensing optical fiber or fibers. The system includes at least one sensing fiber provided along the length of the linear structure, and first and second interrogation and laser pumping sub-systems disposed at opposite ends of the sensing fiber, each of which includes a reflectometer. The reflectometer of the first interrogation and laser pumping sub-system is connected to one end of the sensing fiber. The reflectometer of the second interrogation and laser pumping sub-system is coupled to either (i) an end of a second sensing fiber provided along the length of the linear structure which is opposite from the one end of the first sensing fiber, or (ii) the opposite end of the first sensing fiber.

Abstract: A technique facilitates monitoring of flow conditions with respect to flow through a tubing. A distributed sensor is routed along an interior of the tubing to monitor flow conditions. For example, the distributed sensor may be routed over a length of the tubing having a lateral opening. Fluid is flowed along the distributed sensor and within the interior of the tubing. The distributed sensor is operated to measure strain which results from flow of the fluid along the distributed sensor. The strain may then be evaluated to determine a change in a flow condition, such as a change in a flow condition related to the lateral opening.

Abstract: A system and method for detecting breakage, rupture or malfunctioning of a pipe or cable structure, including sensing elements for monitoring the structure and placed in, on or around the structure for monitoring the breakage, rupture or malfunctioning of the structure. The sensing elements provide sensing data regarding events related to breakage, rupture or malfunctioning and are placed near the structure so as to perform a breakage, rupture or malfunction detection function, and within a distance sufficient to obtain a measureable strain, tension, torsion, vibration, acceleration, and/or temperature response signal based on the breakage, rupture or malfunctioning of the structure. One of the sensing elements is based on Coherent Rayleigh Noise (CRN) sensing techniques, and the system is configured to interpret the sensed data for determining the breakage, rupture or malfunctioning of the structure.

Abstract: A leak detection system and method is provided for a structure having a first barrier to a first fluid and a second barrier to a second fluid, the first barrier and the second barrier defining a space therebetween. The system includes at least one sensor, such as a fiber optic sensor, placed in the space and configured to detect presence of the first fluid or the second fluid in the space due to a fluid leak in the first barrier or the second barrier. The fiber optic sensor may further be configured to measure one or more characteristics of an acoustic emission caused by the leak, and the system and method may be able to estimate the orifice diameter of the fluid leak based on the measured one or more characteristics, and to calculate a leak rate based on the estimated orifice diameter.

Abstract: A system and method for detecting breakage, rupture or malfunctioning of a pipe or cable structure, including sensing elements for monitoring the structure and placed in, on or around the structure for monitoring the breakage, rupture or malfunctioning of the structure. The sensing elements provide sensing data regarding events related to breakage, rupture or malfunctioning and are placed near the structure so as to perform a breakage, rupture or malfunction detection function, and within a distance sufficient to obtain a measureable strain, tension, torsion, vibration, acceleration, and/or temperature response signal based on the breakage, rupture or malfunctioning of the structure. One of the sensing elements is based on Coherent Rayleigh Noise (CRN) sensing techniques, and the system is configured to interpret the sensed data for determining the breakage, rupture or malfunctioning of the structure.

Abstract: An optical fiber sensor system and method for monitoring a condition of a linear structure such as a pipeline is provided which is capable of providing continuous monitoring in the event of a break in the sensing optical fiber or fibers. The system includes at least one sensing fiber provided along the length of the linear structure, and first and second interrogation and laser pumping sub-systems disposed at opposite ends of the sensing fiber, each of which includes a reflectometer. The reflectometer of the first interrogation and laser pumping sub-system is connected to one end of the sensing fiber. The reflectometer of the second interrogation and laser pumping sub-system is coupled to either (i) an end of a second sensing fiber provided along the length of the linear structure which is opposite from the one end of the first sensing fiber, or (ii) the opposite end of the first sensing fiber.

Abstract: A leak detection system and method is provided for a structure having a first barrier to a first fluid and a second barrier to a second fluid, the first barrier and the second barrier defining a space therebetween. The system includes at least one sensor, such as a fiber optic sensor, placed in the space and configured to detect presence of the first fluid or the second fluid in the space due to a fluid leak in the first barrier or the second barrier. The fiber optic sensor may further be configured to measure one or more characteristics of an acoustic emission caused by the leak, and the system and method may be able to estimate the orifice diameter of the fluid leak based on the measured one or more characteristics, and to calculate a leak rate based on the estimated orifice diameter.

Abstract: An optical signal demodulator for demodulating an M-ary phase shift key (PSK) optical signal comprises a plurality of interferometers arranged such that the optical signal is divided between the interferometes. Each interferometer comprises a plurality of interferometer arms, each arm for transmitting a portion of the signal between an input and an output of the interferometer, the interferometer including an optical delay in one arm relative to another arm thereof. The optical delay between arms of an interferometer may be provided by an optical path length difference between the arms. The optical delay between arms of an interferometer may be different for one interferometer to that of another interferometer.