Abstract: A FBG strain sensor arrangement includes a sensor carrier of steel sheet to which a FBG strain sensor is fastened. A protective cover has a first part configured thin and narrow and bonded to the sensor carrier along an optical fiber so that the optical fiber lying underneath is fixed with a fiber Bragg grating on the sensor carrier. The protective cover is enlarged at each end portion of the optical fiber to thereby form a cavity underneath, with edges of the enlarged second part of the protective cover being bonded to the sensor carrier. Arranged in the cavity is an elastic filler which embeds the coupling points in a vibration damping manner. The protective cover with elastic filler accommodates thermal expansions and functions for dynamic measurements by the vibration damping.

Abstract: A weldable strain sensor includes a strain sensor having two end portions in signal communication with signal lines for transmitting a measurement signal. A sensor carrier extends in a direction of the strain sensor and is firmly connected to the strain sensor. The sensor carrier includes two end portions having slots to thereby form tongues defining tongue ends which are directed in opposition to each other. Integrally surrounding the strain sensor and the end portions thereof is a protective cover of solid plastic which is firmly connected to the sensor carrier. The protective cover is configured in a region of the strain sensor narrow and flat and in a region of coupling points of the strain sensor with the signal lines at least twice as wide and at least twice as high as in a region of the strain sensor.

Abstract: A FBG strain sensor arrangement includes a sensor carrier of steel sheet to which a FBG strain sensor is fastened. The FBG strain sensor includes an optical fiber having two end portions, with a Bragg grating provided between the end portions. An optical signal line is coupled to each end portion for transmission of a measurement signal. A protective cover has a first part configured thin and narrow and bonded to the sensor carrier along the optical fiber so that the optical fiber lying underneath is fixed with the Bragg grating on the sensor carrier. The protective cover is enlarged at each end portion of the optical fiber to thereby form a cavity underneath, with edges of the enlarged second part of the protective cover being bonded to the sensor carrier. Arranged in the cavity is an elastic filler which embeds the coupling points in a vibration damping manner.

Abstract: A weldable strain sensor includes a strain sensor having two end portions in signal communication with signal lines for transmitting a measurement signal. A sensor carrier extends in a direction of the strain sensor and is firmly connected to the strain sensor. The sensor carrier includes two end portions having slots to thereby form tongues defining tongue ends which are directed in opposition to each other. Integrally surrounding the strain sensor and the end portions thereof is a protective cover of solid plastic which is firmly connected to the sensor carrier. The protective cover is configured in a region of the strain sensor narrow and flat and in a region of coupling points of the strain sensor with the signal lines at least twice as wide and at least twice as high as in a region of the strain sensor.

Abstract: An FBG strain sensor for measuring strains to curved surfaces, includes a fiber which is fixed between two securing elements whose undersides are designed as adhesive surfaces, the optical fiber and these securing elements being embedded in a protective compound which consists of a soft silicone rubber or a plastic that has comparable mechanical properties, and the fiber being embedded between an upper and a lower thin sliding film or a sliding tube that consists of Teflon or of a plastic which has a low friction coefficient comparable to Teflon, the underside of the lower sliding film or the lower external surface-line of the sliding tube lying in a plane with the adhesive surfaces of the securing elements.

Abstract: An FBG strain sensor for measuring strains to curved surfaces, includes a fibre which is fixed between two securing elements whose undersides are designed as adhesive surfaces, the optical fibre and these securing elements being embedded in a protective compound which consists of a soft silicone rubber or a plastic that has comparable mechanical properties, and the fibre being embedded between an upper and a lower thin sliding film or a sliding tube that consists of Teflon or of a plastic which has a low friction coefficient comparable to Teflon, the underside of the lower sliding film or the lower external surface-line of the sliding tube lying in a plane with the adhesive surfaces of the securing elements.

Abstract: The invention relates to an optical strain gauge (1) using a glass fibre as a strain sensor. The strain gauge comprises a glass fibre comprising a sheath. The sheath has the following composition: a mixture of polyether ether ketone and an admixture of at least 10 weight percent and a maximum of 40 weight percent of an inorganic filler, with a particle size of between 0.08 ?m and 12 ?m. The outer diameter of the sheath is between 0.2 mm and 1.2 mm. The ratio D/d between the outer diameter D of the sheath and the diameter d of the glass fibre is between 2 and 6. A pressure of the sheath on the glass fibre is such that essentially no relative movement can occur between the glass fibre and the sheath.

Abstract: The invention relates to an optical strain gauge using a glass fiber (1) comprising a Bragg grating (2). The glass fiber is coated with a sheath (3) of polyether ether ketone with an admixture of at least 10 weight percent and a maximum of 40 weight percent of an inorganic filler, with a particle size of between 0.08 ?m and 12 ?m. The outer diameter of the sheath (3) is between 0.2 mm and 1.2 mm. The ratio D/d between the outer diameter D of the sheath (3) and the diameter d of the glass fiber (1) is between 2 and 6. A pressure of the sheath (3) on the glass fiber (1) is such that essentially no relative movement can occur between the glass fiber (1) and the sheath (3).

Abstract: An optical strain gage incorporates an optical waveguide or fiber that includes a sensing section with a fiber Bragg grating, which serves for detecting a strain in a strainable member on which the strain gage is mounted. At locations displaced away from the fiber Bragg grating section, on both sides thereof, the optical waveguide is covered by two fastening elements, which secure the optical waveguide in a force-transmitting manner on the strainable member or a bottom support. Between the two fastening elements, a relatively soft elastic fixing material surrounds the optical waveguide and fixes the fiber Bragg grating section on the strainable member or bottom support in a form-fitting and force-isolating manner.

Abstract: The invention relates to a solid core optic fiber (1) as used in optical fiber technology to transfer optical signals, but also to transmit light for illuminating purposes. The solid core optic fiber (1) comprises a glass fiber (2) with a coating (3). The coating (3) comprises the following composition: a mixture of polyetheretherketone and an inorganic filler material in an admixture of at least 10 and a maximum of 40 wt. % having a particle size of 0.08 ?m to 12 ?m. The outer diameter of the coating (3) is 0.2 mm to 1.2 mm. The ratio D/d between the outer diameter D of the coating (3) and the diameter d of the glass fiber (2) is 2 to 6. A pressure of the coating (3) on the glass fiber (2) is such that essentially no relative motion can occur between the glass fiber (2) and the coating (3).

Abstract: The invention relates to an optical strain gauge (1) using a glass fibre as a strain sensor. The strain gauge comprises a glass fibre comprising a sheath. The sheath has the following composition: a mixture of polyether ether ketone and an admixture of at least 10 weight percent and a maximum of 40 weight percent of an inorganic filler, with a particle size of between 0.08 [mu]m and 12 [mu]m. The outer diameter of the sheath is between 0.2 mm and 1.2 mm. The ratio D/d between the outer diameter D of the sheath and the diameter d of the glass fibre is between 2 and 6. A pressure of the sheath on the glass fibre is such that essentially no relative movement can occur between the glass fibre and the sheath.

Abstract: The invention relates to an optical strain gauge using a glass fiber (1) comprising a Bragg grating (2). The glass fiber is coated with a sheath (3) of polyether ether ketone with an admixture of at least 10 weight percent and a maximum of 40 weight percent of an inorganic filler, with a particle size of between 0.08 ?m and 12 ?m. The outer diameter of the sheath (3) is between 0.2 mm and 1.2 mm. The ratio D/d between the outer diameter D of the sheath (3) and the diameter d of the glass fiber (1) is between 2 and 6. A pressure of the sheath (3) on the glass fiber (1) is such that essentially no relative movement can occur between the glass fiber (1) and the sheath (3).

Abstract: The invention relates to a strain gauge, comprising at least one optical waveguide (5) fastened to a thin support (1). The optical waveguide (5) has at least one section (10) with a fiber Bragg grating (6), which serves the detection of strain. The invention is characterized in that the optical waveguide (5) outside of the fiber Bragg grating section (10) is covered on both sides of said section by two fastening elements (3, 4). In this way, the optical waveguide (5) outside of the fiber Bragg grating section (10) is fastened to the support (1) with force fit. Between the two lateral fastening elements (3, 4), a relatively soft elastic fixing element (2) is fastened around the optical waveguide (2), the element fixing at least the fiber Bragg grating section (10) with positive fit to the support (1).