In an optical fiber monitoring system which detects physical disturbance or other parameters such as temperature or strain of a fiber where a monitor signal is transmitted along the optical fiber and analyzed to detect changes which are indicative of an event, a method is provided for periodically checking proper operation of the optical fiber monitoring system. :A fiber disturbance actuator periodically causes a pattern of disturbances of a portion of the fiber at a predetermined location thereon where the disturbance is characteristic of the event to be monitored. The monitor signal is analyzed to detect the pattern of changes and in the event that expected changes are not detected, a warning is issued that the intrusion detection system is not properly operating.

In an optical fiber monitoring system which detects physical disturbance or other parameters such as temperature or strain of a fiber where a monitor signal is transmitted along the optical fiber and analyzed to detect changes which are indicative of an event, a method is provided for periodically checking proper operation of the optical fiber monitoring system. A fiber disturbance actuator periodically causes a pattern of disturbances of a portion of the fiber at a predetermined location thereon where the disturbance is characteristic of the event to be monitored. The monitor signal is analyzed to detect the pattern of changes and in the event that expected changes are not detected, a warning is issued that the intrusion detection system is not properly operating.

A plurality of strain values are received from a plurality of sensors permanently attached to an asset configured to carry a load. A strain profile of the asset is monitored based on the plurality of strain values. Additional information about the asset is received. A load rating factor is monitored based on the additional information and the strain profile. An equivalent accumulated damage factor is monitored based on the load rating factor. A remaining life prediction for the asset is calculated based on the strain profile and the equivalent accumulated damage factor.

Structural component, in particular for a vehicle body, comprising a structural element (12) and a sensor arrangement (16), wherein the sensor arrangement (16) is connected to the structural element (12) and comprises at least one optical waveguide (14).

An apparatus for locating a measurand anomaly, such as a hot-spot, along an optical waveguide is provided having: an optical waveguide, a light source configured to transmit light along the waveguide and a plurality of sensors provided along the waveguide. Each sensor is configured to reflect a portion of light propagating along the waveguide at a respective sensor wavelength corresponding to a measurand. The plurality of sensors is configured into one or more sets according to their sensor wavelengths, each set comprising a plurality of sensors with respective sensor wavelengths, wherein the sensors are configured such that the sensor wavelength for each sensor in a respective set is substantially equal when the measurand experienced by each of the sensors in that set is equal. The apparatus further includes a detector configured to monitor the light reflected by the sensors, and a control system.

An optical inspection system includes an optical fiber sensor, an optical filter, a signal processor, and a corrector. The optical fiber sensor outputs a first optical signal having a temporal change in a wavelength corresponding to a temporal change in an amplitude of a vibration propagating in an inspection target object or a temporal change in a displacement of the inspection target object. The optical filter converts the first optical signal into a second optical signal having a temporal change in an intensity. The signal processor acquires inspection information on the inspection target object on the basis of the second optical signal. The corrector corrects a correspondence relationship between the temporal change in the wavelength and the temporal change in the intensity by changing a wavelength characteristic of the optical filter. The correspondence relationship is directed to converting the first optical signal into the second optical signal.

A sensor system includes a sensor network comprising at least one optical fiber having one or more optical sensors. At least one of the optical sensors is arranged to sense vibration of an electrical device and to produce a time variation in light output in response to the vibration. A detector generates an electrical time domain signal in response to the time variation in light output. An analyzer acquires a snapshot frequency component signal which comprises one or more time varying signals of frequency components of the time domain signal over a data acquisition time period. The analyzer detects a condition of the electrical device based on the snapshot frequency component signal.

The present invention relates to a corrosion-fatigue-coupled test method and device for a steel bridge deck. The method includes: 1) installing an orthotropic steel bridge deck (OSBD) and pasting filter paper; 2) installing a sodium chloride solution delivery pipe; 3) installing an infrared (IR) lamp; 4) preparing a corrosive solution; 5) coupling corrosion and fatigue; and 6) acquiring test data. A device constructed by using the method includes a to-be-tested OSBD, a support device, a pressure pump, a water tank, a monitoring device, an IR lamp, a plastic water pipe, a thermostat and a rotary sprayer. The present invention solves the problem of laboratory accelerated corrosion of the OSBD. The present invention fully considers a coupling effect of a corrosive medium and an alternating stress, so that the created simulation environment is close to a service environment of the OSBD, and the test data are effective and reliable.

Aspects of the present disclosure describe systems, methods and structures and applications of optical fiber sensing. Of significance, systems, methods, and structures according to aspects of the present disclosure may reuse and/or retrofit/upgrade existing optical fiber cables as part of optical fiber sensing that may find important societal application including intrusion detection, road traffic monitoring and infrastructure health monitoring. Combining such optical fiber sensing with artificial intelligence (AI) further enables powerful applications at low(er) cost.

Aspects of the present disclosure describe optical fiber sensing systems, methods and structures disclosing a distributed fiber sensor network constructed on an existing, live network, data carrying, optical fiber telecommunications infrastructure to detect temperatures, acoustic effects, and vehicle trafficamong others. Of particular significance, sensing systems, methods, and structures according to aspects of the present disclosure may advantageously identify specific network locations relative to manholes/handholes and environmental conditions within those manholes/handholes namely, normal, flooded, frozen/iced, etc.