Abstract: The present invention provides a new and unique method for increasing the photosensitivity of a large diameter optical waveguide having a cross-section of at least about 0.3 millimeters. The method features loading the large diameter optical waveguide with a photosensitizing gas at a pressure at least about 4000 pounds per square inch (PSI) at a temperature of at least about 250° Celsius. The photosensitizing gas may be hydrogen, Deuterium or other suitable gas. The method also includes the step of using a particular large diameter optical waveguide having a core more than 1000 microns from the surface thereof. The method may be used as part of a process for writing a Bragg grating in an inner core or a cladding of the large diameter optical waveguide.

Abstract: Flow rate measurement system includes two measurement regions 14,16 located an average axial distance ?X apart along the pipe 12, the first measurement region 14 having two unsteady pressure sensors 18,20, located a distance X1 apart, and the second measurement region 16, having two other unsteady pressure sensors 22,24, located a distance X2 apart, each capable of measuring the unsteady pressure in the pipe 12. Signals from each pair of pressure sensors 18,20 and 22,24 are differenced by summers 44,54, respectively, to form spatial wavelength filters 33,35, respectively. Each spatial filter 33,35filters out acoustic pressure disturbances Pacoustic and other long wavelength pressure disturbances in the pipe 12 and passes short-wavelength low-frequency vortical pressure disturbances Pvortical associated with the vortical flow field 15. The spatial filters 33,35 provide signals Pas1,Pas2 to band pass filters 46,56 that filter out high frequency signals.

Abstract: An apparatus for measuring at least one parameter associated with a fluid flowing within a pipe includes a spatial array of pressure sensors disposed at different axial locations x1. . . xN along the pipe. Each of the pressure sensors provides a pressure signal P(t) indicative of unsteady pressure within the pipe at a corresponding axial location of the pipe. A signal processor receives the pressure signals from each of the pressure sensors and determines the parameter of the fluid using pressure signals from selected ones of the pressure sensors. By selecting different pressure sensors, the signal processor can configure the array to meet different criteria. In one embodiment, the array of pressure sensors may be formed on a single sheet of polyvinylidene fluoride (PVDF) that is wrapped around at least a portion of an outer surface of the pipe. This arrangement allows a large number of pressure sensors to be quickly and economically installed.

Abstract: An optical spectrum analyzer (OSA) 10 sequentially or selectively samples (or filters) a spectral band(s) 11 of light from a broadband optical input signal 12 and measures predetermined optical parameters of the optical signal (e.g., spectral profile) of the input light 12. The OSA 10 is a free-space optical device that includes a collimator assembly 15, a diffraction grating 20 and a mirror 22. A launch pigtail emits into free space the input signal through the collimator assembly 15 and onto the diffraction grating 20, which separates or spreads spatially the collimated input light, and reflects the dispersed light onto the mirror 22. A ?/4 plate 26 is disposed between the mirror 22 and the diffraction grating 20. The mirror reflects the separated light back through the ?/4 plate 26 to the diffraction grating 20, which reflects the light back through the collimating lens 18. The lens 18 focuses spectral bands of light (?1–?N) at different focal points in space.

Abstract: An apparatus for measuring a parameter of a fluid passing through a pipe comprises a spatial array of pressure sensors disposed at different axial locations along the pipe between a sleeve within the pipe and an inside surface of the pipe. Each of the pressure sensors provides a pressure signal indicative of unsteady pressure within the pipe at a corresponding axial location of the pipe. A signal processor is configured to receive the pressure signals from each of the pressure sensors, and determine the parameter of the fluid using the pressure signals from the pressure sensors. The sleeve and the sensors may be disposed within a pipe spool piece having flanges disposed on opposing ends. The pipe may be formed from a material relatively more rigid than the sleeve, and the sensors may be compressed between the pipe and the sleeve. The sleeve may have grooves formed therein for receiving the sensors, and each sensor may be formed from a piezocable wrapped around the sleeve.

Abstract: An apparatus for measuring at least one parameter associated with a fluid flowing within a pipe comprises an optical measurement device and a signal processor. The optical measurement device provides output signals indicative of unsteady pressures within the fluid at two or more axial locations along the pipe in response to light reflected from an outer surface of the pipe. The signal processor provides an output signal indicative of at least one parameter associated with the fluid in response to the output signals. The optical measurement device may include, for example, an electronic speckle pattern interferometer, a Fabry-Perot device, and/or a laser vibrometer. The at least one parameter may include at least one of: density of the fluid, volumetric flow rate of the fluid, mass flow rate of the fluid, composition of the fluid, entrained air in the fluid, consistency of the fluid, size of particles in the fluid, and health of a device causing the unsteady pressures to be generated in the pipe.

Abstract: A flow measurement apparatus is provided that combines the functionality of an apparatus that uses strain-based sensors and ultrasonic sensors to measure the speed of sound propagating through a fluid flowing within a pipe, and measure pressures disturbances (e.g. vortical disturbances or eddies) moving with a fluid to determine respective parameters of the flow propagating through a pipe. The apparatus includes a sensing device that includes an array of pressure sensors used to measure the acoustic and convective pressure variations in the flow to determine desired parameters and an ultrasonic meter portion to measure the velocity and volumetric flow of the fluid. In response to an input signal or internal logic, the processor can manually or dynamically switch between the pressure sensors and ultrasonic sensors to measure the parameters of the flow.

Abstract: An apparatus 10 and method is provided that includes a spatial array of unsteady pressure sensors 15–18 placed at predetermined axial locations x1–xN disposed axially along a pipe 14 for measuring the velocity and volumetric flow rate of a single phase or multi-phase fluid 12 having a non-negligible axial Mach number flowing in 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 propagating with and against the flow of the fluid 12 in the pipe 14 using acoustic spatial array signal processing techniques. The apparatus, responsive to the measured speed of sound propagating with and against the flow of the fluid, determines the velocity and the flow rate of the fluid propagating through the pipe.

Abstract: 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.

Abstract: An optical system has a broadband source and a chirped Bragg grating etalon. In operation, the broadband source provides a broadband optical signal. The chirped Bragg grating etalon responds to the broadband optical signal, for providing a chirped Bragg grating etalon optical signal having a precise set of the optical reference signals. The chirped Bragg grating etalon may include a pair of chirped Bragg gratings. The precise set of the optical reference signals is determined by the spacing of the chirped Bragg gratings of the chirped Bragg grating etalon. The precise set of the optical reference signals includes a series of peaks covering most of a source spectral width of the broad optical source signal with the power at the beginning and end of the spectrum passed unaffected by the chirped Bragg grating etalon due to the limited bandwidth thereof.

Abstract: A parameter of a fluid passing through a pipe is measured using a spatial array of sensors disposed at different axial locations along the pipe. The spatial array includes at least two overlapping sub-arrays. Using the pressure signals, a signal processor determines a spatial correlation matrix for each of the sub arrays. The spatial correlation matrices from the sub-arrays are averaged, and the averaged spatial correlation matrix is used as input to an adaptive array processing algorithm. The pipe may be open ended such that it can be positioned within the fluid flow for forming a portion of a sensing device.

Abstract: A apparatus 10,110 is provided that measures the speed of sound and/or vortical disturbances propagating in a fluid or mixture having entrained gas/air to determine the gas volume fraction of the flow 12 propagating through a pipes and compensating or correcting the volumetric flow measurement for entrained air. The GVF meter includes and array of sensor disposed axially along the length of the pipe. The GVF measures the speed of sound propagating through the pipe and fluid to determine the gas volume fraction of the mixture using array processing. The GVF meter can be used with an electromagnetic meter and a consistency meter to compensate for volumetric flow rate and consistency measurement respective, to correct for errors due to entrained gas/air.

Abstract: A flow measuring system is provided that provides at least one of a compensated mass flow rate measurement and a compensated density measurement. The flow measuring system includes a gas volume fraction meter in combination with a coriolis meter. The GVF meter measures acoustic pressures propagating through the fluids to measure the speed of sound ?mix propagating through the fluid to calculate at least gas volume fraction of the fluid and/or the reduced natural frequency. For determining an improved density for the coriolis meter, the calculated gas volume fraction and/or reduced frequency is provided to a processing unit. The improved density is determined using analytically derived or empirically derived density calibration models (or formulas derived therefore), which is a function of the measured natural frequency and at least one of the determined GVF, reduced frequency and speed of sound, or any combination thereof.

Abstract: An apparatus for measuring a parameter of a fluid passing through a pipe includes a spatial array of at least two sensors disposed at different axial locations along the pipe. Each of the sensors provides a signal indicative of unsteady pressure within the pipe at a corresponding axial location of the pipe. A signal processor constructs at least a portion of a k-? plot using the signals and detects at least one ridge in the k-? plot. A slope of the at least one ridge is indicative of the parameter of the fluid. The signal processor determines a quality metric by comparing an accumulated energy (power) of k-? pairs along the at least one ridge with an accumulated energy (power) of k-? pairs along at least one ray extending in the k-? plot. The quality metric is indicative of a quality of the at least one ridge.

Abstract: An apparatus and method are disclosed wherein at least one parameter associated with a core-annular flow (CAF) in a pipe is measured by sensing unsteady pressures associated with undulations formed at the interface of a core region and an annular region in the CAF at different axial locations along the pipe. The at least one parameter, which may include a flow velocity of the CAF, Mach number associated with the CAF, and a volumetric flow rate of the CAF, is determined using sensed unsteady pressures. The CAF may be developed from a shear thinning fluid, such as bitumen froth or from a wood pulp fiber suspension. Alternatively, the CAF may be developed from a lubricating fluid, such as water, and a fluid to be transported, such as oil, where the fluid to be transported forms the core region and the lubricating fluid forms the annular region.

Abstract: An apparatus measures the speed of sound and/or vortical disturbances propagating in a fluid flow to determine a parameter of the flow propagating through a pipe. The apparatus includes a sensing device that includes an array of pressure sensors used to measure the acoustic and convective pressure variations in the flow to determine a desired parameter. The sensing device includes a unitary strap having a plurality of bands disposed parallel to each other. The bands are interconnected by cross members to maintain the bands a predetermined distance apart. Each of the bands having a strip of piezoelectric film material mounted along a substantial length of the bands. The piezoelectric film material provides a signal indicative of the unsteady pressures within the pipe. The sensing device includes a conductive shield around the multi-band strap and the piezoelectric film material to provide a grounding shield.

Abstract: A method and apparatus are provided for calibrating a flow meter having an array of sensors arranged in relation to a pipe that measures a flow rate of a fluid flowing in the pipe. The method features the step of calibrating the flow rate using a calibration correction function based on one or more parameters that characterize either the array of sensors, the pipe, the fluid flowing in the pipe, or some combination thereof. The calibration correction function depends on either a ratio t/D of the pipe wall thickness (t) and the pipe inner diameter (D); a ratio t/? of the pipe wall thickness (t) and the eddie wavelength (?) of the fluid; a Reynolds number (?UD/?) that characterizes the fluid flow in the pipe; a ratio ?x/D of the sensor spacing (?x) and the pipe inner diameter (D); a ratio f?x/Umeas of usable frequencies in relation to the sensor spacing (?x) and the raw flow rate (Umeas); or some combination thereof.

Abstract: A flow measuring system combines a density measuring device and a device for measuring the speed of sound (SOS) propagating through the fluid flow and/or for determining the gas volume fraction (GVF) of the flow. The GVF meter measures acoustic pressures propagating through the fluids to measure the speed of sound ?mix propagating through the fluid to calculate at least gas volume fraction of the fluid and/or SOS. In response to the measured density and gas volume fraction, a processing unit determines the density of non-gaseous component of an aerated fluid flow. For three phase fluid flows, the processing unit can determine the phase fraction of the non-gaseous components of the fluid flow. The gas volume fraction (GVF) meter may include a sensing device having a plurality of strain-based or pressure sensors spaced axially along the pipe for measuring the acoustic pressures propagating through the flow.

Abstract: A reconfigurable multifunctional optical device has an optical arrangement for receiving an optical signal, each having optical bands or channels, and a spatial light modulator for reflecting the at least one optical signal provided thereon. The optical arrangement features a free optics configuration with a light dispersion element for spreading each optical signal into one or more respective optical bands or channels for performing separate optical functions on each optical signal. The spatial light modulator includes a micro-mirror device with an array of micro-mirrors, and the respective optical bands or channels reflect off respective micro-mirrors. The free optics configuration includes a common set of optical components for performing each separate optical function on each optical signal. The separate optical functions reflect off separate non-overlapping areas on the spatial light modulator. The separate optical functions include optical switching, conditioning or monitoring functions.

Abstract: A dual function flow measurement apparatus is provided that combines the functionality of an apparatus that measures the speed of sound propagating through a fluid flowing within a pipe, and measures pressures disturbances (e.g. vortical disturbances or eddies) moving with a fluid to determine respective parameters of the flow propagating through a pipe. The apparatus includes a sensing device that includes an array of pressure sensors used to measure the acoustic and convective pressure variations in the flow to determine desired parameters. The measurement apparatus includes a processing unit the processes serially or in parallel the pressure signals provided by the sensing array to provide output signals indicative of a parameter of the fluid flow relating to the velocity of the flow and the speed of sound propagating through the flow, respectively.