Fiber optic bragg grating pressure sensor
    1.
    发明授权
    Fiber optic bragg grating pressure sensor 有权
    光纤布拉格光栅压力传感器

    公开(公告)号:US06278811B1

    公开(公告)日:2001-08-21

    申请号:US09399504

    申请日:1999-09-20

    IPC分类号: G02B600

    CPC分类号: G01L11/025

    摘要: A fiber optic Bragg grating pressure sensor particularly suited for measuring ambient pressure of a fluid includes a pressuring detecting device 12 such as a glass element whose elastic deformation is proportional to applied pressure. An optical fiber 28 with an integral first grating 33 is wrapped at least once around the device and has at least a portion of its length fused to the device 12 such that elastic deformation of the device 12 generates a corresponding axial strain in the fiber 28 and/or the grating 33 and thus a corresponding change of the fiber length and/or characteristic reflectance wavelength of the grating 33. A second grating 35 may be formed near the pressure detecting device 12 so as to sense ambient temperature but not be affected by deformation of the device 12 for temperature compensation. Also, the fiber 28 may have more than one grating or be doped at least between a pair of gratings 160,162, to form a fiber laser or a DFB fiber laser which lasing wavelength changes with changing pressure.

    摘要翻译: 特别适用于测量流体环境压力的光纤布拉格光栅压力传感器包括加压检测装置12,例如玻璃元件,其弹性变形与施加的压力成比例。 具有集成的第一光栅33的光纤28至少缠绕在设备周围,并且其长度的至少一部分与设备12融合,使得设备12的弹性变形在纤维28中产生相应的轴向应变,并且 /或光栅33,从而光栅33的光纤长度和/或特征反射波长的相应变化。第二光栅35可以形成在压力检测装置12附近,以便感测环境温度但不受变形影响 的温度补偿装置12。 此外,光纤28可以具有多于一个光栅或者至少在一对光栅160,162之间被掺杂,以形成激光波长随着变化的压力而变化的光纤激光器或DFB光纤激光器。

    Method and apparatus for interrogating fiber optic sensors
    3.
    发明授权
    Method and apparatus for interrogating fiber optic sensors 有权
    用于询问光纤传感器的方法和装置

    公开(公告)号:US06785004B2

    公开(公告)日:2004-08-31

    申请号:US09726059

    申请日:2000-11-29

    IPC分类号: G01B902

    CPC分类号: G01D5/35383 E21B47/102

    摘要: An apparatus and method for interrogating fiber optic sensors non-intrusively sensing fluid flow within a pipe is provided. The apparatus includes a two-beam interferometer which comprises an optical circuit for generating a series of discrete light pulses that are directed at sensors positioned between pairs of low reflectivity fiber Bragg gratings. The successive light pulses are split into first light pulses and second light pulses, and the second light pulses are delayed a known time period relative to the first pulses. The first and second light pulses are combined onto a single optical fiber and directed through the low reflectivity gratings and the sensors positioned between the gratings. Reflected pulses from the series of pulses impinge on a photo receiver and interrogator, wherein the phase shift between the reflected first light pulses from a particular grating and the reflected second light pulses from the preceding grating, for each sensor are determined. Phase shifts from successive pulses for each sensor are compared, and a change in a measured parameter of the fluid is determined.

    摘要翻译: 提供了一种用于询问光纤传感器非侵入式地感测管道内的流体流动的装置和方法。 该装置包括双光束干涉仪,其包括用于产生一系列离散光脉冲的光学电路,其被定向在位于低反射率光纤布拉格光栅对之间的传感器处。 连续的光脉冲被分成第一光脉冲和第二光脉冲,并且第二光脉冲相对于第一脉冲被延迟已知的时间周期。 第一和第二光脉冲被组合到单个光纤上并被引导通过位于光栅之间的低反射率光栅和传感器。 来自一系列脉冲的反射脉冲撞击光接收器和询问器,其中确定来自特定光栅的反射的第一光脉冲与来自前一光栅的反射的第二光脉冲之间对于每个传感器的相移。 比较每个传感器的连续脉冲的相移,并确定流体的测量参数的变化。

    Tube-encased fiber grating
    5.
    发明授权
    Tube-encased fiber grating 有权
    管状光纤光栅

    公开(公告)号:US06519388B1

    公开(公告)日:2003-02-11

    申请号:US09455865

    申请日:1999-12-06

    IPC分类号: G02B634

    CPC分类号: G02B6/022 G02B6/0218

    摘要: A tube-encased fiber grating includes an optical fiber 10 having at least one Bragg grating 12 impressed therein which is embedded within a glass capillary tube 20. Light 14 is incident on the grating 12 and light 16 is reflected at a reflection wavelength &lgr;1. The shape of the tube 20 may be other geometries (e.g., a “dogbone” shape) and/or more than one concentric tube may be used or more than one grating or pair of gratings may be used. The fiber 10 may be doped at least between a pair of gratings 150,152, encased in the tube 20 to form a tube-encased compression-tuned fiber laser or the grating 12 or gratings 150,152 may be constructed as a tunable DFB fiber laser encased in the tube 20. Also, the tube 20 may have an inner region 22 which is tapered away from the fiber 10 to provide strain relief for the fiber 10, or the tube 20 may have tapered (or fluted) sections 27 which have an outer geometry that decreases down to the fiber 10 and provides added fiber pull strength. Also, the tube-encased grating 12 exhibits lower mode coupling from the fiber core to the cladding modes due to the increased diameter of the cladding where the tube 20 is fused to the fiber 10 where the grating is located 12.

    摘要翻译: 管状光纤光栅包括光纤10,其具有嵌入其中的至少一个布拉格光栅12,该布拉格光栅12嵌入玻璃毛细管20内。光14入射到光栅12上,光16以反射波长lambd1反射。 管20的形状可以是其他几何形状(例如,“狗骨”形状)和/或可以使用多于一个的同心管,或者可以使用多于一个的光栅或一对光栅。 纤维10可以至少掺杂在一对光栅150,152之间,封装在管20中以形成管封装的压缩调谐光纤激光器,或者光栅12或光栅150,152可被构造为包含在该光纤12中的可调DFB光纤激光器。 管20也可以具有内部区域22,该内部区域22远离纤维10逐渐变细,以为纤维10提供应变消除,或者管20可以具有锥形(或凹槽)部分27,其具有外部几何形状 降低到纤维10并提供增加的纤维拉伸强度。 此外,由于包层的直径增加,管20被熔合到光栅位于12处的光纤10,管状光栅12表现出从纤维芯到包层模式的较低模式耦合。

    Compression-tuned Bragg grating and laser
    6.
    发明授权
    Compression-tuned Bragg grating and laser 有权
    压缩调谐布拉格光栅和激光

    公开(公告)号:US06363089B1

    公开(公告)日:2002-03-26

    申请号:US09691997

    申请日:2000-10-19

    IPC分类号: H01S310

    摘要: A compression-tuned bragg grating includes a tunable optical element 20,600 which includes either an optical fiber 10 having at least one Bragg grating 12 impressed therein encased within and fused to at least a portion of a glass capillary tube 20or a large diameter waveguide grating 600 having a core and a wide cladding. Light 14 is incident on the grating 12 and light 16 is reflected at a reflection wavelength &lgr;1. The tunable element 20,600 is axially compressed which causes a shift in the reflection wavelength of the grating 12 without buckling the element. The shape of the element may be other geometries (e.g., a “dogbone” shape) and/or more than one grating or pair of gratings may be used and more than one fiber 10 or core 612 may be used. At least a portion of the element may be doped between a pair of gratings 150,152, to form a compression-tuned laser or the grating 12 or gratings 150,152 may be constructed as a tunable DFB laser. Also, the element 20 may have an inner tapered region 22 or tapered (or fluted) sections 27. The compression may be done by a PZT, stepper motor or other actuator or fluid pressure.

    摘要翻译: 压缩调谐布拉格光栅包括可调谐光学元件20,600,其包括光纤10,其具有印刷在其中的至少一个布拉格光栅12,该光纤10被封装在玻璃毛细管20或大直径波导光栅600的至少一部分中并且熔合到其中, 一个核心和宽广的包层。 光14入射到光栅12上,光16以反射波长lambd1反射。 可调谐元件20,600被轴向压缩,这导致光栅12的反射波长的偏移而不使元件弯曲。 元件的形状可以是其他几何形状(例如,“狗骨”形状)和/或可以使用多于一个的光栅或一对光栅,并且可以使用多于一个的光纤10或核612。 元件的至少一部分可以掺杂在一对光栅150,152之间,以形成压缩调谐的激光器,或者光栅12或光栅150,152可被构造为可调DFB激光器。 此外,元件20可以具有内锥形区域22或锥形(或凹槽)部分27.压缩可以由PZT,步进电动机或其他致动器或流体压力来实现。

    Apparatus having an array of piezoelectric film sensors for measuring parameters of a process flow within a pipe
    7.
    发明授权
    Apparatus having an array of piezoelectric film sensors for measuring parameters of a process flow within a pipe 有权
    具有用于测量管道内的工艺流程的参数的压电膜传感器阵列的装置

    公开(公告)号:US07474966B2

    公开(公告)日:2009-01-06

    申请号:US11521627

    申请日:2006-09-14

    IPC分类号: G06F19/00

    CPC分类号: G01F1/712 G01F1/74

    摘要: A apparatus 10,110,170 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, by measuring acoustic and/or dynamic pressures. The apparatus includes a spatial array of unsteady pressure sensors 15-18 placed at predetermined axial locations x1-xN disposed axially along the pipe 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 process flow 12 flowing in the pipe 14. The pressure sensors are piezoelectric film sensors that are mounted or clamped onto the outer surface of the pipe at the respective axial location.

    摘要翻译: 提供了一种装置10,110,170,其测量在单相流体流和/或多相混合物中传播的声速和/或涡流干扰的速度,以确定参数,例如混合质量,粒度,蒸气/质量比,液体/蒸气比, 质量流量,管道中流量的焓和体积流量,通过测量声学和/或动态压力。 该装置包括放置在沿管14轴向设置的预定轴向位置x1-xN处的不稳定压力传感器15-18的空间阵列。压力传感器15-18向信号提供声压信号P1(t)-PN(t) 处理单元30,其确定在管14中流动的工艺流程12传播的声音amix的速度。压力传感器是压电膜传感器,其在相应的轴向位置处安装或夹紧在管的外表面上。

    Strain-isolated Bragg grating temperature sensor
    9.
    发明授权
    Strain-isolated Bragg grating temperature sensor 有权
    应变隔离布拉格光栅温度传感器

    公开(公告)号:US06865194B1

    公开(公告)日:2005-03-08

    申请号:US09455866

    申请日:1999-12-06

    IPC分类号: G01K11/32 H01S3/30 G01N21/00

    CPC分类号: G01K11/32

    摘要: A strain-isolated bragg grating temperature sensor includes an optical sensing element 20,600 which includes an optical fiber 10 having at least one Bragg grating 12 disposed therein which is encased within and fused to at least a portion of a glass capillary tube 20 and/or a large diameter waveguide grating 600 having a core and a wide cladding and having the grating 12 disposed therein, which senses temperature changes but is substantially not sensitive to strains on the element caused by the fiber or other effects. Light 14 is incident on the grating 12 and light 16 is reflected at a reflection wavelength λ1. The shape of the sensing element 20,600 may be other geometries and/or more than one concentric tube may be used or more than one grating or pair of gratings may be used or more than one fiber or optical core may be used. At least a portion of the element 20,600 may be doped between a pair of gratings 150,152, disposed therein to form a temperature tunable laser or the grating 12 or gratings 150,152 may be constructed as a temperature tunable DFB laser disposed in the element. Also, the element may have an inner or outer tapered regions 22,27, respectively, to provide strain relief and/or added pull strength for the fiber 10. Further, the fiber 10 and the tube 20 may be made of different coefficients of thermal expansion for increased sensitivity.

    摘要翻译: 应变隔离布拉格光栅温度传感器包括光学传感元件20,600,光学传感元件20,600包括光纤10,该光纤10具有布置在其中的至少一个布拉格光栅12,该布拉格光栅12被封装在玻璃毛细管20的至少一部分内并且熔合到玻璃毛细管20和/ 大直径波导光栅600具有芯和宽包层并且其中布置有光栅12,其感测温度变化,但对由纤维或其它效应引起的元件上的应变基本上不敏感。 光14入射在光栅12上,光16以反射波长λ1反射。 感测元件20,600的形状可以是其他几何形状,和/或可以使用多于一个的同心管,或者可以使用多于一个的光栅或一对光栅,或者可以使用多于一个的光纤或光纤。 元件20,600的至少一部分可以被掺杂在放置在其中的一对光栅150,152之间以形成温度可调激光器,或者光栅12或光栅150,152可以被构造为设置在元件中的温度可调谐DFB激光器。 此外,元件可以分别具有内部或外部锥形区域22,27,以为纤维10提供应变消除和/或增加的拉伸强度。此外,纤维10和管子20可以由不同的热系数 扩大灵敏度提高。