An optical fiber sensing system, method and apparatus for simultaneously measuring temperature, strain, and pressure are provided and belong to the field of optical fiber sensors. A distributed optical fiber temperature sensor is configured to monitor the temperature, and transmit the monitored temperature to a fiber grating strain and pressure sensor; the fiber grating strain and pressure sensor performs self temperature compensation based on received temperature; and the fiber grating strain and pressure sensor monitors the strain and the pressure. The distributed optical fiber temperature sensor is used to replace a temperature compensation function of the fiber grating strain sensor, and sense temperature distribution of each point along a route. Further, the fiber grating strain and pressure sensor is simplified inside, temperature demodulation is no longer required and speed of obtaining values of the strain and the pressure has been accelerated.

A system for determining pH of a fluid and a method to determine the pH of a fluid contacting a sensor, the method having the steps of: providing the sensor to an environment such that the sensor is in contact with the fluid, wherein the sensor features a fiber extending between a first end and a second end along a longitudinal axis, wherein the fiber further features a medial portion positioned between the first and second ends, wherein the sensor further features a pH sensitive coating on the medial portion of the fiber, and wherein the pH sensitive material features a metal oxide including but not limited to SiO.sub.2, TiO.sub.2, ZrO.sub.2, Ta.sub.2O.sub.5, A.sub.2O.sub.3, and combinations thereof; interrogating the sensor with an optical signal; collecting a modified optical signal after the sensor has been interrogated; and determining the pH of the fluid contacting the pH sensor using the modified optical signal.

An optical connector including a first optical fiber having a first diameter and having a core that includes a thermally expanded core portion adjacent a first end of the first optical fiber, a second optical fiber spliced to a second end of the first optical fiber, the second optical fiber having a second diameter less than the first diameter, and a connector bore having a first bore portion configured to receive the first end of the first optical fiber.

A passive microscopic flow sensor includes a three-dimensional microscopic optical structure formed on a cleaved tip of an optical fiber. The three-dimensional microscopic optical structure includes a post attached off-center to and extending longitudinally from the cleaved tip of the optical fiber. A rotor of the three-dimensional microscopic optical structure is received for rotation on the post. The rotor has more than one blade. Each blade has a reflective undersurface that reflects a light signal back through the optical fiber when center aligned with the optical fiber, the blades of the rotor shaped to rotate at a rate related to a flow rate.

An air pressure sensor based on a suspended-core fiber and a side-hole fiber is provided and includes a broadband light source, an optical fiber circulator, a sensing head and a spectrometer; the optical fiber circulator is connected with the broadband light source, the sensing head and the spectrometer; the sensing head includes a single mode fiber, a multimode fiber, the suspended-core fiber and the side-hole fiber; the single mode fiber is connected with the suspended-core fiber through the multimode fiber; and the multimode fiber is connected with the side-hole fiber through the suspended-core fiber. The sensor uses a fabrication method of fiber fusion, and the operation is simple; the sensor has advantages of small volume, compact structure and convenient use; the sensor has good stability without adhesive; additionally, parallel connection of double cavities could produce vernier effects, so the sensor has good contrast of interference spectrum and high sensitivity.

Embodiments of the present invention provide a unique new approach to generating operating condition information used for assessing flow assurance and structural integrity. More specifically, apparatuses, systems and methods configured in accordance with embodiments of the present invention enable multiplexed arrangement of optical fiber for sensing of operating conditions within a structural member and utilize fiber optic sensors for enabling monitoring of operating condition information within one or more elongated tubular members. To this end, fiber optic sensors are strategically placed at a plurality of locations along a length of each elongated tubular member thereby allowing critical operating conditions such as strain, temperature and pressure of the elongated tubular member and/or a fluid therein to be monitored. A multiplexing unit is used for allowing selective configuration of individual lengths of optical fiber for creating one or more contiguous optical fiber structures.

A processing device disposed inside a transmitter/receiver intended for use in optical fiber sensing using an optical fiber in order to enable restricting utilization of a prescribed range of acquired data, the processing device comprising: a mask unit which masks a prescribed range of acquired data, which is the data acquired by the transmitter/receiver through the optical fiber sensing; and an output unit which outputs post-masking data, which is the data that has undergone the aforementioned masking, to the outside of the transmitter/receiver, wherein the acquired data prior having the masking performed thereon for the prescribed range is not outputted to the outside.

A water pressure fluctuation measuring system detects a water pressure fluctuation. A cable, which includes an optical fiber, is provided on or in the ground of the seabed in such a way that the optical fiber is expanded and contracted according to the water pressure fluctuation. An optical output unit outputs monitoring light to the optical fiber. A partial reflection unit is provided on a path of the optical fiber in the cable and partially reflects the monitoring light. An optical reception unit receives reflection light reflected by the partial reflection unit. A calculation unit measures a length of the optical fiber to the partial reflection unit, based on a round-trip propagation time of the received reflection light, and monitors a change of the length over time.

The invention relates to a method for in-life testing of the formation of the solid electrolyte interface layer of a battery cell, comprising the following steps: sensing the temperature within the battery cell, recording a first set of temperature (T) and/or pressure data related to the temperature variation (ΔT) and/or pressure variation within the battery cell over a first charge of the battery cell, and determining a positive or negative datum relating to the formation of solid electrolyte interface layer of the battery cell according to said first set of temperature and/or pressure data

Embodiments of the present invention provide a unique new approach to generating operating condition information used for assessing flow assurance and structural integrity. More specifically, apparatuses, systems and methods configured in accordance with embodiments of the present invention enable multiplexed arrangement of optical fiber for sensing of operating conditions within a structural member and utilize fiber optic sensors for enabling monitoring of operating condition information within one or more elongated tubular members. To this end, fiber optic sensors are strategically placed at a plurality of locations along a length of each elongated tubular member thereby allowing critical operating conditions such as strain, temperature and pressure of the elongated tubular member and/or a fluid therein to be monitored. A multiplexing unit is used for allowing selective configuration of individual lengths of optical fiber for creating one or more contiguous optical fiber structures.