Sensortran, Inc.

The Texas A&m University System

Other

Wj Semiconductor Equipment Group, Inc.

Chung E Lee

Kent Kalar

Henry F Taylor

Michael Sanders

Kwang Il Suh

Mahesh Ajgaonkar

Brian Vandellyn Park

William H Hallidy

Roberto Sadkowski

Mohammed Fassih-Nia

Robert A Atkins

William N Gibler

Robert X Perez

Matthew O Spears

Victor P Swenson

James Gardner

Ta-Wei Kao

System and method for correcting the potential errors occurring in a fiber optic temperature measurement system are disclosed. In one respect, a dual light sources configuration is provided. The primary light source may illuminate a sensing fiber, and an Anti-Stokes band may be detected. The secondary light source may illuminate a sensing fiber, and a Rayleigh band may be detected, where the Rayleigh band is substantially wide enough to cover the Anti-Stokes band of the primary light source. A ratio between these Anti-Stokes and the Rayleigh bands may be used to measure the temperature and undesired errors due to the perturbations falling on the sensing fiber is continuously corrected.

Method and apparatus for auto correcting the distributed temperature sensing system

Method and apparatus for auto-correcting the distributed temperature sensing system

An automatic and continuous method is presented to improve the accuracy of fiber optic distributed temperature measurements derived from Raman back scatterings utilizing two light sources with different wavelengths, by choosing the wavelengths of the two sources so the primary source's return anti-Stokes component overlaps with the incident wavelength of the secondary light source thereby canceling out the non-identical attenuations generated by the wavelength differences between Stokes and anti-Stokes bands.

Dual source auto-correction in distributed temperature systems

A new step-index multimode pure silica core fiber for DTS (Distributed Temperature Sensing) system particularly useful for downhole environments is disclosed and described. The new sensor system provides optimum tradeoffs between coupling power, spatial resolution, and temperature resolution.

Pure silica core multimode fiber sensors for DTS applications

Systems and methods for extending the range of a fiber optic DTS system are provided. In one respect, a method may provide steps for transmitting, in a first time period, an optical signal at a first energy level through an optical fiber, collecting backscatter signals as a result of the first transmission, adjusting the first energy level to a second energy level, transmitting, in an additional time period, the adjusted optical signal through the optical fiber, collecting backscatter signals as a result of the adjusted transmissions, and using a portion of the collected backscatter as a result of the first transmission and a portion of the collected backscatter as a result of the additional transmissions, determining one or more parameter profiles, such as a temperature profile.

Methods and systems for extending the range for fiber optic distributed temperature (DTS) systems

A distributed sensing system for detecting partial electric discharge along the length of an extended object or objects. An optical fiber having a cladding integrated with luminescent material and a silica core of less than 500 micro-meters in diameter with a first reflective end deployed in proximity to test objects. A photo detector is positioned at the second end of the optical sensing fiber and receives and measures both a direct emission light from an electric partial discharge event and the reflected emission light from the reflection end of the optical sensing fiber. The measured signals and their arrival times are used to determine the location and magnitude of a partial electrical discharge.

Systems and methods for detecting electric discharge

Systems and methods for calibrating a temperature sensing system are disclosed. In one respect, a dual light source configuration may be provided. A first light source may illuminate a sensing fiber and an anti-Stokes band may be detected. A second light source may illuminate a sensing fiber and a Stokes band may be detected, where the Stokes band is substantially similar to the anti-Stokes band of the first light source. A ratio between the anti-Stokes and Stokes band may be used to calibrate a temperature sensing system.

Methods and apparatus for dual source calibration for distributed temperature systems

Systems and methods for detecting corrosion are provided. In one embodiment, a luminescent material coupled to a cladding of an optical fiber may be altered when exposed to corrosion. The backscatter emission of the luminescent material, which includes the altered optical properties, may be used to determine properties of the corrosion including, for example, thickness, or location of the corrosion.

Systems and methods for detecting corrosion

Systems and methods for calibrating a temperature sensing system are disclosed. In one respect, a line may be placed in operative relation with a first reference cell and a second reference cell. The temperatures of the first and second reference cells may be adjusted. In one non-limiting example, the temperature of the first reference cell may be adjusted to a temperature above an ambient temperature and the temperature of the second reference cell may be adjusted to a temperature below an ambient temperature. The temperature sensing system may be calibrated based on the temperature data of the first and second reference cells.

Methods and apparatus for calibrating distributed fiber temperature sensing system

A fiber optic fiber Fabry-Perot interferometer diaphragm sensor and method of measurement is provided. A fiber Fabry-Perot interferometer diaphragm sensor (,) includes a base (,) and a diaphragm (,) with an optic fiber (,) coupled under tension between the base (,) and the diaphragm (,). A fiber Fabry-Perot interferometer element (,) is contained within the optic fiber (,) and operates to sense movement of the diaphragm (,). In a particular embodiment, the diaphragm (,) moves in response to a pressure (P) applied to the diaphragm (,). In another embodiment, a proof mass (,) is coupled to the diaphragm (,) such that the diaphragm (,) moves in response to an acceleration (A). In yet another embodiment, a magnetic body (,) is coupled to the diaphragm (,) such that the diaphragm (,) moves in response to a magnetic field (M).

Fiber optic fiber Fabry-Perot interferometer diaphragm sensor and method of measurement

Amorphously crosslinked aromatic polymeric low .kappa. materials and methods for their fabrication are provided. The subject materials are prepared by a modified transport polymerization process, in which aromatic precursors are pyrolyzed to produce radical comprising aromatic monomeric precursors which are then allowed to polymerize by deposition onto a substrate surface, where during and/or after deposition the growing polymer chain is exposed to a high energy crosslinking agent, such as high energy photons or plasma. The subject crosslinked materials find use in a variety of applications, particularly as low .kappa. dielectrics in the manufacture of integrated circuits.

Method for preparing crosslinked aromatic polymers as low .kappa.

Apparatus and method (10, 50) for determining the value of a measurand measured by a fiber optic interferometer sensor (24, 72, 110) is provided. The apparatus includes a light source (16, 58, 102) emitting a light having a periodically modulated frequency which is injected into the interferometric sensor. A modulation cycle is initiated by the microcontroller's (12, 56, 116) generation of a trigger signal. A counter (42, 86) begins counting in response to the trigger signal. A first photodetector (20, 66) is coupled to the light source (16, 58, 102) and produces a first electrical signal proportional to the light. A second photodetector (36, 76, 114) is coupled to the fiber optic interferometer sensor (24, 72, 110) and produces a second electrical signal proportional to the light reflected by the sensor or passed through the sensor and affected by the measurand. A comparator (40, 82, 116) compares the second electrical signal with the first electrical signal and detects a crossing of the first and second electrical signals. The counter (42, 86) stops counting in response to a detected signal crossing. The microcontroller (12, 56, 116) then computes a measurand value from the count value for each modulation cycle.

Signal conditioning unit for fiber optic sensors

Apparatus for sensing intrusion into a predefined perimeter comprises means for producing a coherent pulsed light, which is injected into an optical sensing fiber having a first predetermined length and positioned along the predefined perimeter. A backscattered light in response to receiving the coherent light pulses is produced and coupled into an optical receiving fiber. The backscattered light is detected by a photodetector and a signal indicative of the backscattered light is produced. An intrusion is detectable from the produced signal as indicated by a change in the backscattered light. To increase the sensitivity of the apparatus, a reference fiber and an interferometer may also be employed.

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College Station, TX, United States of America

Chung E Lee