In the field of measuring physical parameters with a multimode optical fiber, a system for measuring P physical parameters at one or more measurement points has one or more multimode optical fibers. The system includes: a light source generating a source optical signal, a multimode measurement optical fiber transporting optical signals in at least M distinct second predetermined propagation modes, M being an integer greater than or equal to P, the measurement optical fiber including a measurement section reflecting the optical signals with a wavelength variable according to physical parameters to be measured, a detection device measuring wavelengths of the optical signals reflected by the measurement section, and an optical module generating M signals from the source optical signal, the M signals each being injected into the measurement optical fiber to propagate in one of the modes, the optical module also transferring the optical signals reflected toward the detection device.

Damage to a joint part of a terminal of an electronic component mounted on a substrate is detected. The substrate includes a base material unit, a land, and a light detection unit. The land included in the substrate is arranged with a stress light emitting body configured to emit light in accordance with stress, includes a transparent member, and is joined with a terminal of an element arranged in the base material unit included in the substrate. The light detection unit included in the substrate is arranged between the base material unit and the land included in the substrate, and detects light from the stress light emitting body.

Device with isotropic planar compliance comprising a floating body (2) positioned between a first (3) and second frame (4), said floating body having an extended portion (21) protruding through the first frame, at least a row of caged balls (5) supporting the floating body, at least one elastic element (6) positioned over the extended portion of the floating body, compressed between and connecting the floating body and the first frame. Said caged balls allow the at least one elastic element to laterally deform, so that their axis bends, while the ends of said at least one elastic element lay on two parallel planes, which remain at constant distance while sliding one with respect to the other. The device comprises also at least one displacement sensor (10), for measuring the displacement of the floating body with respect to the first or second frame.

Device with isotropic planar compliance comprising a floating body (2) positioned between a first (3) and second frame (4), said floating body having an extended portion (21) protruding through the first frame, at least a row of caged balls (5) supporting the floating body, at least one elastic element (6) positioned over the extended portion of the floating body, compressed between and connecting the floating body and the first frame. Said caged balls allow the at least one elastic element to laterally deform, so that their axis bends, while the ends of said at least one elastic element lay on two parallel planes, which remain at constant distance while sliding one with respect to the other. The device comprises also at least one displacement sensor (10), for measuring the displacement of the floating body with respect to the first or second frame.

A monitoring system includes an array of optical sensors disposed within a transformer tank. Each optical sensor is configured to have an optical output that changes in response to a temperature within the transformer tank. An analyzer is coupled to the array of optical sensors. The analyzer is configured to determine a sensed temperature distribution based on the sensed temperature. The sensed temperature distribution is compared to an expected distribution. Exterior contamination of the transformer tank is detected based on the comparison.

A wellbore optical fiber measurement system for measuring data in a lateral wellbore that includes a flexible optical fiber. The optical fiber includes a waveguide coated with a coating, wherein the optical fiber has an effective density ρ.sub.eff.sub.fiber and an effective axial Young modulus E.sub.eff.sub.fiber and wherein the product $\left(\frac{{\rho }_{{\mathrm{eff}}_{fiber}}}{E_{{\mathrm{eff}}_{fiber}}}\right).Math.\left(1-\frac{{\rho }_{water}}{{\rho }_{{\mathrm{eff}}_{fiber}}}\right)$
is greater than 50 kg/m3/GPa. The system also includes a data acquisition unit with a processor operable to obtain strain measurement data of the wellbore from the optical fiber.

A sensor network comprises at least one lateral optical fiber and at least one longitudinal optical fiber. The lateral fiber comprises optical sensors coupled to a pavement in a transverse orientation relative to a direction of vehicle travel along the pavement. The longitudinal fiber comprises optical sensors coupled to the pavement in a longitudinal orientation relative to the direction of vehicle travel. The optical sensors are configured to produce wavelength shift signals comprising one or more lateral strain signals associated with the lateral fiber and one or more tangential strain signals associated with the longitudinal fiber. A processor is operatively coupled to the sensor network and configured to determine a weight of vehicles moving along the pavement based on the lateral and tangential strain signals. A transmitter is operatively coupled to the processor and configured to transmit the weight of vehicles to a predetermined location.

A stretchable strain sensor may exhibit wavelength selectivity according to a thickness change of a thickness of the stretchable strain sensor, in a thickness direction extending parallel to the thickness of the stretchable strain sensor, due to elongation of the stretchable strain sensor in an elongation direction extending perpendicular to the thickness direction. The stretchable strain sensor may have an emission spectrum that changes according to strain variation of a strain on the stretchable strain sensor.

Described herein are systems and methods for determination of rolling resistance from a sensor or sensors in a tire or tires for application in smart cars to provide feedback to interested parties, such as Departments of Transportation or tire manufacturers.

The present invention relates to a stress-strain testing system for a large-diameter steel pipe pile of an offshore wind turbine and a construction method, comprising a steel pipe pile, wherein copper belt type sensor cables are correspondingly welded on both sides of the steel pipe pile along an axis direction; each sensor cable is sequentially covered with an epoxy adhesive, gold foil paper and an angle steel welded on the steel pipe pile centering on the copper belt type sensor cable; a fiber core of each copper belt type sensor cable is transferred into a high-strength armored optical cable by a special fixture and then is led out; and the high-strength armored optical cable is connected with a Brillouin optical fiber demodulator. The present invention is applicable to the field of foundation engineering testing and detection technology.