Abstract: Systems and methods for performing the dynamic anomaly localization of utility pole aerial/suspended/supported wires/cables by distributed fiber optic sensing. In sharp contrast to the prior art, our inventive systems and methods according to aspects of the present disclosure advantageously identify a “location region” on a utility pole supporting an affected wire/cable, thereby permitting the identification and reporting of service personnel that are uniquely responsible for responding to such anomalous condition(s).

Abstract: An optical fiber distributed acoustic sensor system makes use of a specially designed optical fiber to improve overall sensitivity of the system by a factor in excess of 10. This is achieved by inserting into the fiber weak broadband reflectors periodically along the fiber. The reflectors reflect a small proportion of the light from the DAS incident thereon back along the fiber, typically in the region of 0.001% to 0.1%. To allow for temperate compensation to ensure that the same reflectivity is obtained if the temperature changes, the reflection bandwidth is relatively broadband. The reflectors are formed from a series of fiber Bragg gratings, each with a different center reflecting frequency, the reflecting frequencies and bandwidths of the gratings being selected to provide the broadband reflection. The reflectors are spaced at the desired spatial resolution of the optical fiber DAS.

Abstract: Various embodiments are described herein for an imaging device and associated method for performing fluence compensation on a photoacoustic (PA) image of at least a portion of an object for sets of RF acoustic response signals that are obtained using different illumination wavelengths. A first set of RF acoustic response signals is fluence matched to a second set of RF acoustic response signals by determining relative frequency data for first set of RF acoustic response signals relative to the second set of RF acoustic response signals and using the relative frequency data to filter the first set of RF acoustic response signals.

Abstract: An optical probe receives an optical signal output from a test subject. The optical probe includes an optical waveguide composed of a core portion and a cladding portion disposed on an outer periphery of the core portion, wherein an incident surface of the optical waveguide, which receives the optical signal, is a convex spherical surface with a constant curvature radius.

Abstract: Aspects of the present disclosure describe Rayleigh fading mitigation via short pulse coherent distributed acoustic sensing with multi-location beating-term combination. In illustrative configurations, systems, methods, and structures according to the present disclosure employ a two stage modulation arrangement providing short interrogator pulses resulting in a greater number of sensing data points and reduced effective sectional length. The increased number of data points are used to mitigate Rayleigh fading via a spatial combining process, multi-location-beating combining (MLBC) which uses weighted complex-valued DAS beating results from neighboring locations and aligns phase signals of each of the locations, before combining them to produce a final DAS phase measurement. Since Rayleigh scattering is a random statistic, the MLBC process allows capture of different statics from neighboring locations with correlated vibration/acoustic signal.

Abstract: A vibration measurement apparatus 10 is an apparatus for measuring vibrations of an object 30. The vibration measurement apparatus 10 includes: a surface-direction displacement calculation unit 11 configured to calculate, based on time-series images of a measurement target area that are output from an imaging apparatus 20, a displacement in a surface direction of the measurement target area; a normal-direction displacement calculation unit 12 configured to calculate a displacement in a normal direction of the measurement target area, based on the time-series images and the displacement in the surface direction of the measurement target area; and a vibration calculation unit 13 configured to calculate vibrations of the object 30, based on the calculated displacement in the surface direction of the measurement target area and the calculated displacement in the normal direction of the measurement target area.

Abstract: Disclosed herein is a system and method for inspecting a bonded structure in a component. The system includes an integrated probe and a processor coupled to the integrated probe. The integrated probe includes an ultrasonic component and a laser component. The ultrasonic component is configured to transmit pulsed sound waves into the bonded structure and receive reflected pulsed sound waves from the bonded structure. The laser component is configured to generate laser pulses and direct the laser pulses to the bonded structure to generate tension waves across the bonded structure. The processor is configured to test a bonded structure in the component. Further, the processor includes a pre-test module configured to operate the ultrasonic component in a pre-test mode, a test module configured to operate the laser component in a test mode, and a post-test module configured to operate the ultrasonic component in a post-test mode.

Abstract: Provided are a photoacoustic image generation apparatus, a photoacoustic image generation method, and a photoacoustic image generation program that can perform a more appropriate reconstruction process regardless of the type of probe, without causing a reduction in the speed of an arithmetic process. It is identified whether a probe that detects photoacoustic waves and outputs a photoacoustic wave detection signal is a probe in which detection elements are arranged by a coordinate system using polar coordinates or a probe in which detection elements are arranged by a rectangular coordinate system. In a case in which the probe is identified as the probe in which the detection elements are arranged by the coordinate system using the polar coordinates, a time domain reconstruction process is selected to generate a photoacoustic image.

Abstract: A multi-modal biosensor system includes a vibrating plate orientated along a plane. An actuator is interfaced with the vibrating plate and operable to vibrate the vibrating plate along the plane. The actuator includes two electrodes rigidly affixed to the vibrating plate. An optical support structure is rigidly affixed to the vibrating plate, and provides an outwardly facing surface to receive a measurement sample. A light source is configured to project light onto the outwardly facing surface of the optical support structure. A light detector is configured to capture light reflected from the outwardly facing surface of the optical support structure. A controller interfaces with the two electrodes and the light detector. The controller operates to detect changes in the vibrating motion of the vibrating plate concurrently with detecting changes in the light captured by the light detector.

Abstract: An optical system is provided and includes a fixed assembly, a movable member, a driving assembly and a buffering member. The movable member is movably connected to the fixed assembly and is configured to hold an optical member having an optical axis. The driving assembly is for driving the movable member to move relative to the fixed assembly. The buffering member is disposed on a first surface of the fixed assembly. The buffering member, the movable member and the fixed assembly are arranged along the optical axis. The buffering member includes a soft resin material. The buffering member is disposed to surround the optical axis.

Abstract: A long-distance FODAS amplification system includes a distributed amplification unit, which includes a LEAF, a pump, and a WDM; wherein the pump light passes through the WDM into the LEAF, so as to realize distributed amplification. A long-distance FODAS amplification method includes steps of: 1) modulating and amplifying a light source to obtain the probe pulse light; 2) guiding the pump light and the probe pulse light into LEAF; 3) combining the probe pulse light with the pump light to perform distributed amplification, so as to generate power-raised Rayleigh backscattered light; and 4) converting and demodulating the Rayleigh backscattered light after being output through the circulator, so as to complete distributed sensing.

Abstract: Systems and methods include a number of optical pulses are transmitted by transmitting, by a distributed acoustic sensor (DAS), where the optical pulses are transmitted at an input port associated with a multimode fibers (MMF) used by the DAS, and where the fundamental mode of the MMF is excited. A number of backscattered Rayleigh signals are collected by the DAS. The Rayleigh signals are recorded as an output intensity profile. A position along the MMF that is subject to vibrations and corresponding vibration parameters are determined by analyzing the recorded output intensity profile.

Abstract: Method and apparatus can be provided according to an exemplary embodiment of the present disclosure. For example, with at least one first section of an optical enclosure, it is possible to provide at least one first electro-magnetic radiation. In addition, with at least one second section provided within the enclosure, it is possible to cause, upon impact by the first radiation, a redirection of the first radiation to become at least one second radiation. Further, with at least one third section of the optical enclosure, it is possible to cause at least one second radiation to be provided to a tissue. For example, the redirection of the first radiation causes, at least approximately, a uniform optical illumination on of a surface of the tissue.

Abstract: According to the present invention, there is provided an electroacoustic transducer, comprising: a first electrode; a second electrode; a piezoelectric material at least partially sandwiched between the first electrode and the second electrode; and an optical aperture extending through the electroacoustic transducer, to allow for optical communication to take place through the electroacoustic transducer.

Abstract: The invention relates to an apparatus for vibration measurement on a machine, having a base plate for mounting on a measurement point of the machine, a magnetic retaining device for holding the base plate at the measurement point by magnetic force, a sensor for detecting vibrations, arranged on or in contact with the base plate, a sensor for detecting the magnetic flux density in the area of the retaining device, and a monitoring device for monitoring the coupling of the base plate to the measurement point by evaluating the detected magnetic flux density.

Abstract: An optical probe for a gas turbine engine includes a housing. Also included is a plurality of optical fibers, a portion of each of the optical fibers secured to fiber holders. Further included is an optical head disposed within the housing and having channels extending in a longitudinal direction of the optical head, the fiber holders disposed within the channels. Yet further included is a cap disposed within the housing and operatively coupled to the optical head, the plurality of optical fibers extending through the cap. Also included is an inner tube operatively coupled to the cap, the plurality of fibers extending through the inner tube.

Abstract: The present disclosure is directed to a vehicle dynamics monitor for an autonomous vehicle. In particular, the systems and methods of the present disclosure can determine, based on data received from one or more sensors of an autonomous vehicle, that an anomaly exists in an interface between at least one tire of the autonomous vehicle and a road surface. Responsive to determining that the anomaly exists: a motion plan for the autonomous vehicle that takes into account the anomaly can be determined; and one or more controls of the autonomous vehicle can be interfaced with to implement the motion plan.

Abstract: A vibration sensing optical fiber cable is provided. The cable includes at least one optical fiber embedded in the cable jacket such that vibrations from the environment are transmitted into the cable jacket to the optical fiber. The cable is configured in a variety of ways, including through spatial arrangement of the sensing fibers, through acoustic impedance matched materials, through internal vibration reflecting structures, and/or through acoustic lens features to enhance sensitivity of the cable for vibration detection/monitoring.

Abstract: An optoacoustic imaging system includes a handheld probe and first and second pulsed light sources having a common output. The first and second light sources generate pulses of light at first and second predominant wavelengths, respectively. The handheld probe includes an ultrasound transducer array having an active end located at the distal end of the handheld probe for receiving an optoacoustic return signal. A sensor measures a portion of the light transmitted along the light path. A data acquisition samples the ultrasound transducer array during a predetermined period of time after a pulse of light from the first light source and during a predetermined period of time after a pulse of light from the second light source. The sampled data is stored.

Abstract: A laser system is provided. The laser system comprises: a seed laser configured to produce a sequence of seed light pulses, wherein the sequence of seed light pulses are produced with variable time intervals in a sweep cycle; a pump laser configured to produce pump light having variable amplitude in the sweep cycle; and a control unit configured to generate a command to the pump laser to synchronize the pump light with the sequence of seed light pulses.

Abstract: Methods and systems are disclosed for measuring multidimensional stress characteristics in a substrate. Generally, the methods include applying a sequence of optical pump pulses to the substrate. The optical pump pulses induce a propagating strain pulse in the substrate. Optical probe pulses are also applied. By analyzing transient optical responses caused by the propagating strain pulse, multidimensional stress components characterizing the stress in the substrate can be determined. Multidimensional stress components may also be determined at a depth of a substrate. Multidimensional stress components may also be determined at areas adjacent a through-silicon via.

Abstract: Methods and systems for Brillouin optical time-domain reflectometry include optically filtering out non-Brillouin signals reflected from a fiber. Brillouin signals reflected from the fiber are coupled with a local oscillator to produce a Brillouin shift signals. The Brillouin shift signals are converted to an electrical domain using a photodetector. The electrical Brillouin shift signals are converted to a digital domain using a low-speed analog-to-digital converter that has a sampling rate below a Nyquist rate sufficient to fully resolve the electrical Brillouin shift signals.

Abstract: A system and method for detecting the rotation breakaway of a spacer from a compressor rotor disk are disclosed herein. The method includes detecting a disk sensed feature and a spacer sensed feature on the compressor rotor disk and the spacer respectively. The method also includes comparing the timing between the two to a predetermined threshold to determine whether the relative position of the spacer to the compressor rotor disk exceeds a predetermined amount. The predetermined amount may be selected to determine whether an imbalance, rubbing, or binding can occur in the gas turbine engine or to determine whether anti-rotation features have been broken.

Abstract: Provided are an apparatus and a method for measuring a nonlinearity parameter using laser, and more particularly, an apparatus and a method for measuring a nonlinearity parameter using laser for computing the nonlinearity parameter by irradiating laser of a toneburst signal on a surface of a sample by non-contact type laser so as to excite the sample, irradiating measurement laser beam on the surface of the sample so as to receive displacement information occurring on the surface of the sample over time, measuring the displacement in an interferometer principle, and performing a bandpass filtering for the measured signal so as to measure amplitude A1 of a component of a fundamental frequency and amplitude A2 of a component of a secondary harmonic wave.

Abstract: An example system for detecting mud pulses may include a distributed acoustic sensing (DAS) data collection system coupled to a downhole drilling system, and an information handling system communicably coupled to the DAS data collection system. The information handling system may include a processor and memory coupled to the processor. The memory may contain a set of instructions that, when executed by the processor, cause the processor to receive quadrature DAS data signals from the DAS data collection system, determine a first template signal associated with mud pulses, transform the determined first template signal into analytic representation form, perform a matched filter operation using the quadrature DAS data signals and the transformed first template signal, and analyze an output signal of the matched filter operation to detect mud pulses in the downhole drilling system.

Abstract: A method of determining rotor blade axial displacement (bij). The rotor blade tip (34) comprises first and second measurement features (36, 38) arranged to make an acute angle therebetween. Measure time of arrival (tijk) of the once per revolution feature (1), first and second edges (40, 42) of the first measurement feature (36), and first and second edges (44, 46) of the second measurement feature (38), for at least two revolutions of the rotor (2). Convert these to circumferential distances (dijk) for each revolution. Calculate a feature angle (?ijk) between each measurement feature (36, 38) and the once per revolution feature (1) for each revolution. Calculate blade untwist angle (?ij) from the change in feature angle (?ijk) between measured revolutions. Calculate the rotor blade axial displacement (bij) from the blade untwist angle (?ij) and the circumferential distance (dijk) of the point from one of the measurement features (36, 38).

Abstract: An optical probe includes a first end, a second end, an outer housing, an inner housing concentric with the outer housing, flow holes within the inner housing at the first end, and an optics holder within the inner housing between the flow holes and the second end. The optical probe further includes high temperature optical lenses inside the optics holder between the flow holes and the second end, fiber holders inside the optics holder between the high temperature optical lenses and the second end, optical fibers coated in a high temperature material extending from inside fiber holders towards the second end, and a high temperature adhesive for securing the optical fibers, the fiber holders, and the high temperature optical lenses.

Abstract: The application describes techniques for monitoring the rate of flow of fluid in a conduit (205) using fiber optic distributed acoustic sensing which are especially applicable to flow in oil and gas wells. The techniques also allow for calibration of the position of the channels of a fiber optic distributed acoustic sensor arranged along a fluid carrying conduit. The techniques comprise introducing a first acoustic stimulus (303) travelling in one direction and a second acoustic stimulus (304) travelling in the opposite direction. Flow of the fluid (v) results in a difference in the propagation velocity of the two acoustic stimuli. The first and second acoustic stimuli create a standing wave and the beat effect due to the flow induced wavelength variation is detected and used to determine flow rate. The acoustic stimulus may be introduced to travel through the conduit to provide the first stimulus and to reflect from the end of the conduit and travel back as the second acoustic stimulus.

Abstract: Reducing disturbance during fiber optic sensing. An in-well fiber optic sensing system includes a device insulated to be disturbance-resistant. The device is in a fiber optic communication path between a source and a target configured to be received in a well. The device is configured to receive a parameter sensing signal transmitted from the source to the target and produce a reference signal. The fiber optic sensing system includes a signal interrogation system connected to the device in the fiber optic communication path. The signal interrogation system is configured to receive the reference signal from the device and to receive a response signal from the target in response to the parameter sensing signal. The response signal represents the parameter of interest. The signal interrogation system is configured to determine the parameter of interest based, in part, on the reference signal and the response signal.

Abstract: A Distributed Acoustic Sensing(DAS) fiber optical assembly comprises adjacent lengths of optical fiber A, B with different directional acoustic sensitivities, for example by providing the first length of optical fiber A with a first coating 35, such as acrylate, and the second length of optical fiber B with a second coating 36, such as copper, wherein the first and second coatings 35 and 36 may be selected such that the Poisson's ratio of the first length of coated fiber A is different from the Poisson's ratio of the second length of coated fiber B. The different Poisson's ratios and/or other properties of the adjacent lengths of optical fiber A and B improve their directional acoustic sensitivity and their ability to detect broadside (radial) acoustic waves.

Abstract: An aircraft jet engine system includes at least one gas turbine engine having a fan including a rotor and a plurality of fan blades. A sensor system in the fan section senses information about the operation of the blades and provides feedback on the condition of each blade to a control. The control is programmed to take in the sensed information and identify a safe operating range for the gas turbine engine based upon damage information developed from the sensed information with regard to each of the blades. An aircraft jet engine system incorporating a plurality of gas turbine engines wherein safe operating ranges are developed for each of the gas turbine engines is also disclosed as is a method of operating an aircraft jet engine system.

Abstract: Apparatuses and methods for detecting hidden or modified objects in a vehicle are disclosed. Embodiments include detection of vehicle irregularities, such as irregularities in the acoustical response of a vehicle tire as the tire rolls over a surface, irregularities in the orientation of the vehicle body, the response of a vehicle component (such as an axle, wheel, tire, etc.) to the vehicle moving over a surface, and the response of a vehicle component to vehicle generated vibrations. In alternate embodiments subsystems detecting different irregularities communicate with one another.

Abstract: Provided are a capacitive transducer that can make a sealing film thickness necessary to seal a gap smaller and can enhance performance such as a wider bandwidth, and a method of manufacturing the capacitive transducer. The capacitive transducer including cells each including a vibration film including a second electrode that is provided with a gap from a first electrode can be manufactured in the following manufacturing method. A convex part is formed on the first electrode, a sacrifice layer having a thickness larger than the thickness of the convex part is formed on the first electrode and the convex part, and a membrane is formed on the sacrifice layer. Further, an etching hole is formed in the membrane at a position above the convex part, the sacrifice layer is etched through the etching hole, and the etching hole is sealed by a sealing layer.

Abstract: A photoacoustic wave measurement device according to the present invention includes: an optical fiber that outputs pulsed light; an external spacer that is disposed between a pulsed-light output end of the optical fiber and a measurement object, and which is adapted to allow the pulsed light to pass therethrough; a piezoelectric element that receives a photoacoustic wave generated by the pulsed light from the measurement object and converts the photoacoustic wave into an electric signal; and a spacer that is disposed between the external spacer and the piezoelectric element, and which is adapted to allow the photoacoustic wave to pass therethrough. The piezoelectric element is farther from the measurement object than the pulsed-light output end. A part of the optical fiber is disposed within the spacer.

Abstract: An illustrative distributed acoustic sensing system includes a multi-mode optical fiber cable for distributed sensing and a distributed acoustic sensing interrogator coupled to the multi-mode optical fiber cable via a single mode optical fiber. The interrogator derives distributed acoustic measurements from Rayleigh backscattering light that is initiated with a substantially under-filled launch configuration that is designed to excite only the lowest-order modes of the multi-mode optical fiber. Mode conversion within the multi-mode optical fiber is anticipated to be negligible. For elastic scattering (i.e., Rayleigh scattering), it is further anticipated that the scattered light will be primarily returned in the incident propagation mode, thereby escaping the extraordinarily large coupling loss that would otherwise be expected from coupling a single-mode optical fiber to a multi-mode optical fiber for distributed sensing. Experiments with graded index multi-mode optical fiber have yielded positive results.

Abstract: A system and method of providing a protective cover to occupants of a room, which includes detecting an occurrence of a threatening event with a protection system deployed in the room, such as detecting gunfire with the protection system and/or receiving a transmitted command of the threatening event by the protection system, and emitting an obscuring haze into the room from a haze generator of the protection system in response to the detected occurrence of the gunfire. The emitted obscuring haze obscures the light of sight contact between a shooter and the occupants in the room, which provides a measure of cover for the occupants while other assistance is being organized. This reduces the chances that the shooter will be able to accurately shoot any victim, increasing the odds of victim survival.

Abstract: An acoustic wave measuring apparatus includes a light source for radiating a light having a wavelength component in wavelength areas, light filters arranged in a light path from the light source to a subject and each to shut off or transmit the light in one of the wavelength areas, a detector for detecting an acoustic wave generated by the radiation, a controller for generating conditions having different combinations of the wavelength components contained in the light, and a signal processor for calculating an optical absorption coefficient of the subject for the light in each wavelength area based on a pressure of the acoustic wave detected under each of the conditions and a strength of the radiated light for each wavelength area under conditions.

Abstract: A system and method for measuring the vibration of a structure of interest are disclosed. The disclosure provides an acoustic isolation structure to substantially reduce response to acoustic energy generated by external physical stimuli. The acoustic isolation structure is formed by placing a housing, such as an outer conduit, around an inner conduit, forming a gap between the housing and the inner conduit. The gap is then configured to serve as an acoustic isolation layer by either filling the gap with an acoustic isolation material or by substantially evacuating the gap and sealing the ends thereof.

Abstract: An optoacoustic system includes first and second light sources capable of generating pulse of light at first and second wavelengths, optical output control, first and second light sync detectors, and a combiner. A power meter that is calibrated to determine power at the first and second predominant wavelength measures power at the first wavelength after the first light sync is detected and measures power at the second wavelength after the second light sync is detected. The system includes a calibration mode wherein it reduces optical output of the first light source when the power measured by the power meter at the first wavelength after the first light sync is detected is above a first level, and reduces optical output of the second light source when the power measured by the power meter at the second wavelength after the second light sync is detected is above a second level.

Abstract: An acoustic sensing system includes, an optical fiber, a plurality of pairs of reflectors distributed along the optical fiber at specific areas where acoustic energy data is sought, a source of coherent radiation in operable communication with the optical fiber, and a detector in operable communication with the optical fiber configured to detect a different wavelength of coherent radiation reflected from each of the plurality of pairs of reflectors including a portion of the coherent radiation reflected from the reflector nearer the detector after having reflected from the reflector further from the detector that define one of the pairs of reflectors.

Abstract: A photoacoustic wave measurement device includes a pulsed-light outputter, an arrangement member and a photoacoustic wave detector. The pulsed-light outputter outputs a pulsed light. The arrangement member is disposed between a pulsed-light output end of the pulsed-light outputter and a measurement object, the arrangement member being adapted to allow the pulsed light to pass therethrough. The photoacoustic wave detector receives a photoacoustic wave generated by the measurement object by the pulsed light and converts the photoacoustic wave into an electric signal. The photoacoustic wave detector is farther from the measurement object than the pulsed-light output end. The arrangement member has such a sufficient thickness that noise to be detected by the photoacoustic wave detector after a start time of detection of the photoacoustic wave starts to be detected after an end time of the detection of the photoacoustic wave.

Abstract: A system (100) for determining a property of an object (106) comprises an inducing arrangement (102), a detector (104) and a processor. The inducing arrangement (102) is configured to generate an impulse of fluid and for directing the impulse of fluid towards the object to induce a physical vibration of the object (106). The inducing arrangement (102) does not contact the object 106 when inducing the physical vibration of the object (106). The detector (104) is configured to detect the physical vibration of the object (106). The detector (104) does not contact the object 106 when detecting the physical vibration of the object (106). The processor is coupled to the detector (104) for determining the property of the object (106) based on at least the detected physical vibration.

Abstract: Systems and techniques are provided for transmitting a light towards a plurality of acousto-optic retro reflectors, arranged as an array, that are configured to physically react to an acoustic signal. The physical reaction modulates the transmitted light which is reflected back towards a light detector and analyzed. The analysis may include detecting an acoustic signal source location and/or reconstructing the acoustic signal. A light scanner may be configured to transmit the light towards the plurality of acousto-optic retro reflectors in a predetermined, continuance, or dynamically determined sequence.

Abstract: An optical sensor is proposed. The optical sensor comprises a first substrate, a second substrate, a membrane, and an optical gate. The first substrate has a concave structure having a first optical micro-reflection surface and a second optical micro-reflection surface formed thereon. The second substrate has a second concave structure having a third optical micro-reflection surface and a fourth optical micro-reflection surface formed thereon. The optical gate is disposed on the membrane within the first concave structure. The membrane is disposed between the first substrate and the second substrate.

Abstract: A kit for detecting the presence of an explosive includes a pulsed focused energy source located at a target distance away from a substrate, the energy having a magnitude sufficient to release the internal energy of an explosive if present on the substrate and thereby generate an acoustic wave. The kit also includes a detector adapted to detect the acoustic wave at a detection distance away from the substrate.

Abstract: This application relates to conditions monitoring of structures forming part of a transport network, e.g. structural health monitoring of structures, especially tunnels. The method involves performing distributed acoustic sensing (DAS) on at least one optical fibre (104) deployed so as to monitor the structure (206). The acoustic response to movement of traffic (205) on the network in the vicinity of the structure is detected and analysed to detect the acoustic response (303, 304) of the structure. The acoustic response of the structure is then analysed to detect any change in condition. The method thus uses the normal movement of traffic on the network, e.g. trains on a rail network, to acoustic excite the structure and detects the resultant response. The method is particularly useful for condition monitoring of tunnels on a rail network.

Abstract: An acoustic isolation chamber. The chamber comprises a housing defining a volume. A first region of the volume is configured to receive a photoacoustic sensor head. A second region of the volume is configured to receive the UUT. A sound proofing means encompassing at least a portion of the volume.

Abstract: A quencher for a flow cell battery is described. The quencher utilizes a quench solution formed from FeCl2 in a dilute HCl solution in order to quench chlorine emissions from the flow cell battery. A quench sensor is further described. The quench sensor monitors the concentration level of FeCl2 in the quench solution and may also monitor the level of the quench solution in the quencher.

Abstract: A method of measuring a wall thickness of a pipe can include optically detecting vibration of the pipe, and computing the wall thickness of the pipe, the computing being based at least partially on the optically detected vibration. Another method of measuring a wall thickness of a pipe can include optically detecting temperature of the pipe, and computing the wall thickness of the pipe, the computing being based at least partially on the optically detected temperature. Another method of measuring a wall thickness of a pipe can include optically detecting vibration and temperature of the pipe, and computing the wall thickness of the pipe, the computing being based at least partially on the optically detected vibration and temperature.

Abstract: A vibration detection system comprises a light source, a biconical tapered fiber comprising a biconical fiber taper and a detector is disclosed. The emission light emitted by the light source is directed to the biconical tapered fiber in one side. A detector is coupled to the other end of the biconical tapered fiber to measure the intensity of the light passing through. When the biconical tapered fiber is exposed to an external vibration, the biconical fiber taper deforms and modulates the light intensity accordingly. The received signal is then fed to the microcomputer to determine the amplitude and frequency of the external vibration. A method of vibration detection is also disclosed.