Distributed fiber optic sensors formed by covering the fibers with tubing are provided. The tubing including responsive materials formulated or configured to, responsive to exposure to one of a target chemical species and a target radiation particle, change a relative size and generate a localized effect on or in the optical fiber.

Distributed fiber optic chemical and radiation sensors formed by coating the fibers with certain types of response materials are provided. For distributed chemical sensors, the coatings are reactive with the targets; the heat absorbed or released during a reaction will cause a local temperature change on the fiber. For distributed radiation sensors, coating a fiber with a scintillator enhances sensitivity toward thermal neutrons, for example, by injecting light into the fiber. The luminescent components in these materials are taken from conjugated polymeric and oligomeric dyes, metal organic frameworks with sorbed dyes, and two-photon-absorbing semiconductors. The compositions may exhibit strong gamma rejection. Other scintillators combining luminescent materials with neutron converters are available. With a multiple-layer coating, it may be possible to identify the presence of both neutrons and gamma rays, for example. Coatings may be applied during manufacture or in the field.

Leakage detection for pressurized fuel tanks. To provide facilitated leakage detection, a leakage detection device for pressurized fuel tanks for storing a pressurized fuel includes a fuel-sensing tracer and a light-wave conducting component. The fuel sensing tracer is configured to alter its optical properties in the presence of a predetermined fuel. The light-wave conducting component is in optical contact with the fuel sensing tracer. Light travelling within the light-wave conducting component is modifiable by altered optical properties of the fuel sensing tracer such that modified light is indicative of the presence of fuel at the location of the fuel sensing tracer.

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.

Provided are an optical sensor and an analyzer, including an optical sensor section in which a cladding layer of an optical fiber is removed so as to expose a core layer by a predetermined optical path length, and a protective material is added to a surface of the exposed core layer, the protective material having higher resistance to an organic solvent, base, or acid than that of the cladding layer; a light source device that causes light to enter one end of the optical fiber; a light receiving device that receives transmitted light emitted from another end of the optical fiber; and a control device that controls the light source device and the light receiving device to measure optical transmittance in the optical sensor based on a ratio of intensity of the light emitted from the light source device to intensity of the light received by the light receiving device.

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.

A method for testing an optical assembly (1) which has an optical microstructure (3) integrated with a substrate (2). The optical microstructure (3) is positioned to form an external optical interaction area (4) on a part of a surface (5) of the substrate (2). A cover cap (6) seals at least a part of the surface (5) of the substrate (2) adjacent to the optical microstructure (3) to obtain a sealed cavity (9). An optical feedthrough (10) is integrated in the substrate (2) to form an external communication path from within the sealed cavity (9). The optical feedthrough (10) allows communication of a physical parameter value which is measured inside the sealed cavity (9) to outside the sealed cavity (9). The physical parameter value is associated with a measure of hermeticity of the sealed cavity (9).

A portable oil leak detection system having an oil sensor mountable to an engine and configured to detect the presence of oil and a processor positioned within a portable housing. The processor is configured to receive a signal indicative of the oil sensor detecting oil, record a timestamp in response to receiving the signal indicative of the oil sensor detecting oil, and activate an alert indicating that the oil sensor has detected oil.

A method for monitoring a fluid carrying conduit by introducing an acoustic pulse into the conduit, and interrogating an optic fibre positioned along the path of said conduit to provide distributed acoustic sensing. By measuring the response at each of a plurality of locations, a conduit condition profile can be derived. A condition profile can be obtained quickly and easily with minimum disruption to the pipeline infrastructure and contained flow. Existing optic fibres running along the path of a pipe can be employed for sensing purposes, allowing relatively long spans of pipeline to be monitored with only limited access to the pipe.

Disclosed are embodiments of hydrocarbon leak detection cables that utilize time domain reflectometry to indicate the location of changes in impedance in a hydrocarbon leak detection cable. In addition, an embodiment of a hydrocarbon leak detection optical fiber is disclosed.