A switchgear includes an optical monitoring system for examining switchgear switching positions. At least one isolating switch is accommodated in an encapsulated housing. The encapsulated housing is disposed in an installation housing. The encapsulated housing has a first transparent window in one region. A fiber-optic system leads from an outer side of the installation housing to the first transparent window.

Disclosed herein is an optical cable comprising a support; flexible protective tubes helically wound around the support, each flexible protective tube comprising an optical fiber comprising an optical core; a cladding disposed on the core; and a primary coating external to the cladding; and a deformable material surrounding the optical fiber; an outer jacket surrounding the flexible protective tubes; wherein each optical fiber is about 0.5% to about 1.5% longer than its respective flexible protective tube; wherein an allowable strain on the optical cable with substantially zero stress on the optical fibers is determined by equations (1) and (2) below:

[00001]$\begin{array}{cc}\mathrm{.Math.}=\underset{\_}{\sqrt{{{}^2\left(D+\frac{d}{2}\right)}^2+p^2}}.Math..Math.\underset{\_}{\sqrt{{{}^2\left(D-\frac{d}{2}\right)}^2+p^2}}.Math..Math.\underset{\_}{{}^2.Math.\mathrm{dD}}-\underset{\_}{10.Math..Math.\mathrm{dD}};& \left(1\right)\\ \mathrm{.Math.}100=\mathrm{Percent}.Math..Math.\mathrm{elongation}.Math..Math.\mathrm{or}.Math..Math.\mathrm{contraction};& \left(2\right)\end{array}$

where d is the amount of optical fiber clearance for free movement within the flexible protective tube, D is an average helical dia

An evaluation unit 10 for a sensor arrangement for railway monitoring is described, the evaluation unit 10 comprising a connection to a position sensor 11 and a connection to a tracking sensor 12. The position sensor 11 is capable of detecting rail vehicles 19 passing over the position of the position sensor 11 on a railway track 14 and provides a position output signal 15. The tracking sensor 12 comprises a fibre optic sensor 16, which is capable of detecting the position of noise along the railway track 14 and the tracking sensor 12 provides a tracking output signal 18. The evaluation unit 10 provides an output signal 13 that depends on the position output signal 15 and the tracking output signal 18. Further, a sensor arrangement for railway monitoring and a method for evaluation of railway monitoring signals are described.

A heat pipe assembly of a nuclear apparatus includes a number of elongated heat pipes and a detection system having one or more fiber optic cable assemblies that are elongated and are wrapped in a helical fashion along an exterior surface of one or more of the heat pipes. The detection system further includes an optical signal generator that supplies to each, fiber optic assembly an optical signal and additionally includes a sensor that detects a number of reflections of the optical signal and generates an output. The output is usable by an instrumentation and control system to determine a number of temperatures along one or more of the heat tubes by detecting a temperature at each of a plurality of locations along each fiber optic cable assembly.

A distributed measurement system includes a first distributed optical sensing fiber deployed along a first desired measurement path and a second distributed optical sensing fiber deployed along a second desired measurement path. The system further includes an interrogation system coupled to the first distributed optical sensing fiber and to the second distributed optical sensing fiber. The system also includes a first distributed measuring instrument launch a first interrogating probe pulse set comprising a first pulse having a first frequency and a second pulse having a second frequency. The interrogation system is designed to direct the first pulse to the first distributed optical sensing fiber and the second pulse to the second distributed optical sensing fiber.

The disclosed embodiments provide a method for tamper-proof protection of containers used for shipment of goods. An optical fiber is embedded in an Optical Shield Wallpaper which lines all interior surfaces of any size of a shipping container, package, box, barrel or other shaped container. Wallpaper is manufactured using large scale rollers that press fibers with encapsulated adhesives onto an appropriate medium. Small medicine containers are protected with a fiber optic shield and sensors manufactured using ink jet printing techniques. Light is applied to the optical fiber and a measurement of optical fiber characteristics is performed. Digital signal processing is used to generate pedigree information, which may include items such as shipping location, serial numbers and lot numbers for the goods. The status of the autonomous anti-tampering system is monitored real-time for unauthorized intrusions. Intrusions detected are relayed to an authorized recipient via a variety of communication channels.

A sensor for detecting an amount of current flowing in a wire wherein displacement of a sensing mirror is used in an interferometer to enable determination of the amount of current. The sensor includes a magnetostrictive element located within a magnetic field formed by the wire. The sensor also includes a position sensor that detects a size increase of the magnetostrictive element. In addition, the sensor includes an amplifying device that amplifies the size increase of the magnetostrictive element by a predetermined amplification factor to provide an amplified size increase. Further, the sensor includes a displacement device that displaces the sensing mirror by an amount corresponding to the amplified size increase.

A vibration sensing optical fiber cable is provided. The cable includes at least one optical fiber embedded in the cable jacket such that vibrations from the environment are transmitted into the cable jacket to the optical fiber. The cable is configured in a variety of ways, including through spatial arrangement of the sensing fibers, through acoustic impedance matched materials, through internal vibration reflecting structures, and/or through acoustic lens features to enhance sensitivity of the cable for vibration detection/monitoring.

A non-acoustic measurement unit is provided to be integrated into an all-optical acoustic antenna, the non-acoustic measurement unit including a portion of an optical fiber, termed non-acoustic, intended to convey non-acoustic measurements, at least one non-acoustic sensor with electrical output able to deliver at least one electrical signal representative of at least one physical quantity, and a passive electro-optical transducer subjected to the electrical signal, the passive electro-optical transducer acting on a mechanical constraint undergone by a first sensitive zone of the optical fiber portion, in such a way that a value of a measurable property of a first optical signal conveyed by the non-acoustic optical fiber is representative of the electrical signal, and at least one photovoltaic cell coupled electrically to the non-acoustic sensor so as to electrically supply the sensor.

An opto-mechanical resonator including a waveguide formed by a plurality of first strips spaced apart from one another; and two mirrors disposed facing one another, which mirrors are optically reflective over at least part of a guide wavelength range of the waveguide. The waveguide extends between the two mirrors, and forms therewith an optically resonant cavity. At least part of the waveguide is held such that it is suspended over a substrate by at least one deformable mechanical element.