摘要:
A sensor head characterizes unsteady pressures in a fluid flowing within a pipe, as may be caused by one or both of acoustic waves propagating through the fluid within the pipe and/or pressure disturbances that convect with the fluid flowing in the pipe. The sensor head comprises a rigid support structure and at least one transducer attached to the rigid support structure. The rigid support structure holds the transducer in contact with an outer surface of the pipe. The at least one transducer senses relative movement between the outer surface of the pipe and the support structure and provides a signal indicative of unsteady pressures within the fluid at a corresponding axial position of the pipe in response to the relative movement. The support structure may be attached to each transducer in an array of transducers, and may include a handle secured thereto for manipulating the sensor head into contact with the pipe. Output signals from the transducers are provided to a processing unit, which processes the output signals to provide a signal indicative of at least one parameter of the flow process.
摘要:
A probe 10,170 is provided that measures the speed of sound and/or vortical disturbances propagating in a single phase fluid flow and/or multiphase mixture to determine parameters, such as mixture quality, particle size, vapor/mass ratio, liquid/vapor ratio, mass flow rate, enthalpy and volumetric flow rate of the flow in a pipe or unconfined space, for example, using acoustic and/or dynamic pressures. The probe includes a spatial array of unsteady pressure sensors 15-18 placed at predetermined axial locations x1-xN disposed axially along a tube 14. For measuring at least one parameter of a saturated vapor/liquid mixture 12, such as steam, flowing in the tube 14. The pressure sensors 15-18 provide acoustic pressure signals P1(t)-PN(t) to a signal processing unit 30 which determines the speed of sound amix propagating through of the saturated vapor/liquid mixture 12 in the tube 14 using acoustic spatial array signal processing techniques. Frequency based sound speed is determined utilizing a dispersion model to determine the parameters of interest.
摘要翻译:提供探针10,170,其测量在单相流体流和/或多相混合物中传播的声速和/或涡旋扰动的速度,以确定参数,例如混合物质量,粒度,蒸汽/质量比,液体/蒸气比, 质量流量,管道或无侧限空间中的流量的焓和体积流量,例如使用声学和/或动态压力。 探头包括放置在沿着管14轴向布置的预定轴向位置x 1 -x N 1 / N 2的非稳态压力传感器15-18的空间阵列。 用于测量在管14中流动的饱和蒸汽/液体混合物12(例如蒸汽)的至少一个参数。 压力传感器15-18向信号处理单元30提供声压信号P 1(t)-P N N(t),该信号处理单元30确定声速a
摘要:
A method and device for pressure sensing using an optical fiber having a core, a cladding and a Bragg grating imparted in the core for at least partially reflecting an optical signal at a characteristic wavelength. The cladding has two variation regions located on opposite sides of the Bragg grating to allow attachment mechanisms to be disposed against the optical fiber. The attachment mechanisms are mounted to a pressure sensitive structure so as to allow the characteristic wavelength to change according to pressure in an environment. In particular, the variation region has a diameter different from the cladding diameter, and the attachment mechanism comprises a ferrule including a front portion having a profile substantially corresponding to at least a portion of the diameter of the variation region and a butting mechanism which holds the ferrule against the optical fiber.
摘要:
A method and device for tuning an optical device including an optical fiber having a core, a cladding and a Bragg grating imparted in the core to partially reflect an optical signal at a reflection wavelength characteristic of the spacing of the Bragg grating. The cladding has two variation regions located on opposite sides of the Bragg grating to allow attachment mechanisms to be disposed against the optical fiber. The attachment mechanisms are mounted to a frame so as to allow the spacing of the Bragg grating to be changed by an actuator which tunes the reflection wavelength. In particular, the variation region has a diameter different from the cladding diameter, and the attachment mechanism comprises a ferrule including a front portion having a profile substantially corresponding to diameter of the variation region and a butting mechanism butting the ferrule against the optical fiber.
摘要:
A creep-resistant optical fiber attachment includes an optical fiber 10, having a cladding 12 and a core 14, having a variation region 16 (expanded or recessed) of an outer dimension on of the cladding and a structure, such as a ferrule 30, disposed against least a portion of the variation region 16. The fiber 10 is held in tension against the ferrule and the ferrule 30 has a size and shape that mechanically locks the ferrule 30 to the variation 16, thereby holding the fiber 10 in tension against the ferrule 30 with minimal relative movement (or creep) in at least one axail direction between the fiber 10 and the ferrule 30. The ferrule 30 may be attached to or part of a larger structure, such as a housing. The variation 16 and the ferrule 30 may have various different shapes and sizes. There may also be a buffer layer 18 between the cladding 12 and the ferrule 30 to protect the fiber 10 and/or to help secure the ferrule 30 to the fiber 10 to minimize creep.
摘要:
The present invention provides a method for making a multicore large diameter optical waveguide having a cross-section of at least about 0.3 millimeters, two or more inner cores, a cladding surrounding the two or more inner cores, and one or more side holes for reducing the bulk modulus of compressibility and maintaining the anti-buckling strength of the large diameter optical waveguide. The method features the steps of: assembling a preform for drawing a multicore large diameter optical waveguide having a cross-section of at least about 0.3 millimeters, by providing an outer tube having a cross-section of at least about 0.3 millimeters and arranging two or more preform elements in relation to the outer tube; heating the preform; and drawing the large diameter optical waveguide from the heated preform. In one embodiment, the method also includes the step of arranging at least one inner tube inside the outer tube.
摘要:
A method of applying a metal coating to optical element, such as an optical waveguide, comprising the steps of partially depleting stabilizers in an electroless metallic solution and immersing an optical waveguide in the electroless metallic solution to deposit the metal coating to the optical waveguide. The step of partially depleting may include creating an electroless metallic solution having a sodium hypophoshite concentration of about 25 grams per liter. The electroless metallic solution may comprise a Fidelity solution 4865A, a Fidelity solution 4865B and de-ionized water in a ratio of 1:1:18; and sodium hypophosphite crystals. Alternatively, the step of partially depleting may include placing a dummy load into the electroless metallic solution. The dummy load may be a rectangular block of metal, formed of a low carbon steel, and may have a threaded cylindrical passage therein. After depleting the stabilizers, the optical waveguide is immersed in the electroless metallic solution for a predetermined length of time depending on a desired deposition thickness.
摘要:
The present invention provides a method for making a multicore large diameter optical waveguide having a cross-section of at least about 0.3 millimeters, two or more inner cores, a cladding surrounding the two or more inner cores, and one or more side holes for reducing the bulk modulus of compressibility and maintaining the anti-buckling strength of the large diameter optical waveguide. The method features the steps of: assembling a preform for drawing a multicore large diameter optical waveguide having a cross-section of at least about 0.3 millimeters, by providing an outer tube having a cross-section of at least about 0.3 millimeters and arranging two or more preform elements in relation to the outer tube; heating the preform; and drawing the large diameter optical waveguide from the heated preform. In one embodiment, the method also includes the step of arranging at least one inner tube inside the outer tube.
摘要:
A piezocable based sensor for measuring unsteady pressures inside a pipe comprises a cable wrapped around the pipe and an outer band compressing the cable towards the pipe. The cable provides a signal indicative of unsteady pressure within the pipe in response to expansion and contraction of the pipe. The cable includes: a first electrical conductor, a piezoelectric material disposed around the first electrical conductor, a second electrical conductor disposed around the piezoelectric material, and an insulative jacket surrounding the piezoelectric material and electrical conductors. The cable may be part of an array of cables wrapped around the pipe, and a signal processor may determine a parameter of the fluid using the signals. A housing is disposed around the pipe and electrical components associated with the pipe. Ends of the housing include a sealing arrangement, which provides a seal between the ends of the housing and the pipe.
摘要:
A tunable optical filter has a large diameter cane waveguide with “side-holes” in the cane cross-section that reduce the force required to compress the large diameter optical waveguide without overly compromising the buckling strength thereof. The large diameter optical waveguide has a cross-section of at least about 0.3 millimeters, including at least one inner core, a Bragg grating arranged therein, a cladding surrounding the inner core, and a structural configuration for providing a reduced bulk modulus of compressibility and maintaining the anti-buckling strength of the large diameter optical waveguide. The structural configuration reduces the cross-sectional area of the large diameter optical waveguide. These side holes reduce the amount of glass that needs to be compressed, but retains the large diameter.