A cable (10) includes a cable body (11) that is formed from a plurality of wires (14) that are integrally bundled; and a pair of sockets (12) to which both end portions of the cable body (11) is separately affixed; at least one of the plurality of wires (14) being a fiber-containing wire (16), which is formed by an optical fiber (17) that extends in a cable length direction (D) and that is protected by a protective tube (18); wherein the optical fiber (17) protrudes from the protective tube (18), in the cable length direction, further outside than the socket (12); and each of the pair of sockets (12) is provided with a spool (30) that removably holds the optical fiber (17) and imparts an initial tensile strain to the optical fiber (17).

The present invention relates to an optical fiber sensor for shape sensing, comprising an optical fiber having embedded therein a number of at least four fiber cores (1 to 6) arranged at a distance from a longitudinal center axis (0) of the optical fiber, the number of fiber cores (1 to 6) including a first subset of at least two fiber cores (1, 3, 5) and a second subset of at least two fiber cores (2, 4, 6), the fiber cores (2, 4, 6) of the second subset being arranged to provide a redundancy in a shape sensing measurement of the fiber sensor (12′). The fiber cores (1, 3, 5) of the first subset are distributed in azimuthal direction around the center axis (0) with respect to one another, and each fiber core (2) of the second subset is arranged in non-equidistantly fashion in azimuthal direction around the center axis (0) with respect to two neighboring fiber cores (1, 3) of the first subset.

Apparatus and methods for acquiring strain profiles of an optical conductor of a wireline cable in a wellbore, either while the cable is lowered and/or at intervals during the lowering when the cable is briefly stationary. Changes in the acquired strain profiles are utilized to infer or otherwise determine changes in the disposition of the cable.

There are described methods, systems, and computer-readable media for detecting events in a conduit. Multiple lengths of optical fiber positioned alongside a conduit are used to detect a signal. For each length of optical fiber, interferometric data is obtained from the detected signal. The interferometric data obtained for one length of optical fiber is compared to the interferometric data obtained for one or more other lengths of optical fiber. Based on the comparison, it is determined whether the signal originated from the conduit.

A method of optical sensing comprises coupling an excitation optical signal into a first optical fiber to induce Rayleigh backscattering, thereby providing a backscattered signal. The backscattered signal is optically amplified in the first optical fiber, thereby providing an amplified backscattered signal. The amplified backscattered signal is coupled into a second optical fiber and is optically re-amplifying in the second optical fiber.

A fabrication method of the multi-core fiber Bragg grating (FBG) probe for measuring structures of a micro part based on the capillary self-assembly technique, wherein the diameter of the fiber (6) inscribed with FBG is reduced using a mechanical method or an etch method by the hydrofluoric acid; the fibers (6) inscribed with FBG, whose diameter has been reduced, are inserted into a tube (7) through its terminal with an inner taper angle; the FBG terminals of these fibers (6) are immersed into the UV adhesive (10) of a low viscosity and the UV adhesive (10) is raised in the gaps between the fibers (6); or the UV adhesive is dropped on the these fibers (6) and the capillary bridge between the fibers (6) is formed; a most compact structure of the fiber bundle is formed as a result of the capillary self-assembly; the fiber bundle is cured using a UV light and the multi-core FBG (11) is therefore formed; the terminal of the multi-core FBG (11) is polished with an optic fiber polishing machine and then a spherical tip is fabricated with the melting fiber method or the installation method of a micro ball; therefore, a multi-core FBG (11) probe can be achieved. The method features low crosstalk between signal of FBG, inexpensive and low insertion loss.

The invention relates to a device for detecting acceleration. The device contains: a frame; a mass; a lever arm connected to the mass, wherein the mass is provided at a first lever position; an optical fiber having a fiber-optic sensor; and a compensation element for disturbance variables, wherein the compensation element for disturbance variables is connected to the lever arm or the mass and wherein the compensation element for disturbance variables is connected to the frame.

A battery pack includes at least one battery cell, an optical fiber sensing unit including a plate-type detection unit made of optical fibers horizontally and vertically arranged in a grid form. The plate-type detection unit is deformed by deformation of the at least one battery cell, a photoresistor to collect light reflected from the optical fiber sensing unit, and a controller configured to determine if swelling occurred in the at least one battery cell based on a resistance value with a change in an amount of light collected by the photoresistor.

A generator, in particular of a wind power installation, for generating electric current, comprising a rotor and a stator having stator teeth and grooves arranged between said stator teeth for receiving at least one stator winding, wherein a measuring device is provided to determine the deflection of at least one stator tooth of the stator in connection with the generator, wherein the measuring device is connected to at least one measuring unit, which is embodied as a strain gauge.

An optical shape sensing method is provided. The method comprises: providing first and second optical fibre portions arranged to receive light from at least one common lasers such that a path length of the light from the laser to the first optical fibre portion differs from a path length of the light from the lasers to the second optical fibre portion by a first distance; wherein the first and second optical fibre portions are spaced apart from each other in a first direction; and wherein the first and second optical fibre portions comprise a plurality of reflectors spaced along the length of the optical fibre portions, wherein the reflectors are arranged in sets of reflectors, each set including one reflector from each of the optical fibre portions, wherein the reflectors in each set are aligned with one another in a second direction that is perpendicular to the first direction when the optical fibre portions are in neutral positions; supplying light from the laser to the optical fibre portions; detecting an interferometric signal from the optical fibre portions at a common detector; determining, for each set of reflectors, optical path length differences between the reflectors in the set of reflectors based on the detected interferometric signal; determining a curvature of the optical fibre portions in the first direction based on the optical path length differences, between the reflectors in the first and second optical fibre portions, for the sets of reflectors. An optical shape sensor and optical shape sensing system are also provided.