Abstract: A ladar device that has a linear frequency-modulated laser source that produces a primary beam. An optical shear generator spectrally shears the primary beam into no less than three sensing beams. An optical output delivers at least one of the sensing beams toward a target. The sensing beams reflect from the target to produce reflected beams. An optical receiver receives the reflected beams and produces reflected beam signals corresponding to characteristics of the reflected beams. A processor receives the reflected beam signals and produces a deviation matrix, without the use of a local oscillator. The deviation matrix is used to produce a reconstruction of the target, which is output on an electrical signal output.

Abstract: A frequency resolved optical gating (FROG) system receives an ultrafast laser pulse as the “unknown wave” input to the system. The FROG system preferably generates a spectrogram (FROG trace) of the input pulse using a polarization gate, second harmonic generation or other FROG geometry. The system or method preferably analyzes the spectrogram using constrained outer products and principal component generalized projections to find characteristics of the unknown wave such as intensity and phase. Examples of constrained outer products include outer products that incorporate an external constraint such as spectral information or an internal constraint such as a relationship between the probe and gate components derived from the unknown wave.

Abstract: The present disclosure provides surge arrester units having one or a plurality of sensor assemblies within the surge arrester unit. The sensor assemblies include a first plate, a second plate, a heat absorption member positioned between the first and second plates, and a temperature assembly that senses the temperature of the heat absorption member and transmits the temperature.

Abstract: A three-dimensional integrated circuit includes a first layer including at least one sensing element configured to output at least one temperature-dependent voltage; and a second layer disposed vertically with respect to the first layer and coupled to the first layer by at least one via. The second layer includes: a compare circuit configured to generate at least one intermediate voltage in response to comparing the at least one temperature-dependent voltage to a feedback voltage; a control circuit configured to generate at least one control signal in response to the intermediate voltage; and a switching circuit configured to couple a capacitor coupled to a feedback node to one of a first voltage supply and a second voltage supply in response to the at least one control signal to generate an output signal that is based on a temperature sensed by the sensing element.

Abstract: The present techniques are directed to a pipeline transporting a production fluid including hydrocarbon. An optical fiber is disposed along a length of the pipeline. A control system determines a predicted operating temperature based on pressure and flow rate of the production fluid in the pipeline. The control system determines a measured temperature along the pipeline using the optical fiber. The control system detects and locates a temperature anomaly by comparing the measured temperature of the pipeline to the predicted operating temperature.

Abstract: In some implementations, a system performs proactive performance tests for an appliance before a time for an operational change in usage of the appliance. Usage data for an appliance associated with a property may be obtained. The obtained usage data indicates past activity of the appliance and present operational status of the appliance. Weather forecast data associated with a location of the property can be obtained. A time for an operational change in usage of the appliance can be predicted based at least on the obtained usage data for the appliance and the obtained weather forecast data. An operation directed to conducting one or more performance tests on the appliance can be performed before the predicted time for the operational change in usage of the appliance. One or more communications related to the one or more performance tests of the appliance can be provided to a client device.

Abstract: A zero-heat-flux, deep tissue temperature measurement system measures internal body temperature by way of a probe having a heater and thermal sensors arranged in a zero-heat-flux construction. The measurement system includes control mechanization that determines heater and skin temperatures based upon data obtained from the probe and uses those temperatures to calculate a deep tissue temperature. The measurement system includes a signal interface cable having a connector where a probe can be releasably connected to the system. The cable and attached connector are a removable and replaceable part of the system, separate from the probe. The measurement system provides an output signal imitating a standard input signal configuration used by other equipment.

Abstract: A stitched sensor including a plurality of threads stitched to a textile in a stitch geometry is described. The plurality of threads includes a conductive thread, and the stitch geometry is configured such that an electrical property of the stitched sensor changes based on at least one of stretching, relaxation, or bending of the textile. Methods for forming a stitched sensor are also described.

Abstract: A torque detecting apparatus includes a first shaft; a second shaft; an elastic member coaxially linking the first and second shafts; and a magnet attached to the first shaft; a pair of magnetic yokes composed of a first magnetic yoke and a second magnetic yoke, the first and second magnetic yokes being fixedly installed on the second shaft; and a magnetic sensor. Each magnetic yoke includes an opposing portion and a wall portion. The opposing portion is opposed to the magnet and displaced circumferentially relatively to the magnet when the elastic member is subjected to a torsional displacement. The wall portions of the first and second magnetic yokes are separated and positioned outside the opposing portions in the radial direction. The wall portions of the first and second magnetic yokes extend to be mutually opposed. The magnetic sensor is positioned between the wall portions.

Abstract: The present application discloses implementations that relate to devices and techniques for sensing position, force, and torque. Devices described herein may include a light emitter, photodetectors, and a curved reflector. The light emitter may project light onto the curved reflector, which may reflect portions of that projected light onto one or more of the photodetectors. Based on the illuminances measured at the photodetectors, the position of the curved reflector may be determined. In some implementations, the curved reflector and the light emitter may be elastically coupled via one or more spring elements; in these implementations, a force vector representing a magnitude and direction of a force applied against the curved reflector may be determined based on the position of the curved reflector.

Abstract: A pressure sensing device including a light source, at least one resonant structure, a cladding body, a first substrate and a second substrate is provided. The light source is configured to provide an original broadband light. The resonant structure includes a plurality of semiconductor rod structures arranged into a row at intervals along a single arranging direction, and each of the semiconductor rod structures has a lattice constant on the arranging direction. The original broadband light is transmitted between the semiconductor rod structures, and a resonant light is produced, wherein each of the semiconductor rod structures has a length perpendicular to the arranging direction and has a width parallel to the arranging direction, the length and the width are less than the wavelength of the resonant light. The cladding body completely covers the semiconductor rod structures of the at least one resonant structure.

Abstract: A sensor module and a joint are made of different metal materials. The sensor module includes a first portion located near a diaphragm and a second portion having a large-diameter portion whose diameter is larger than that of the first portion. A step engaged with a peripheral edge of the large-diameter portion is formed on the joint. The large-diameter portion and the joint are mutually bonded through a bonding portion. The bonding portion is bonded by a plastic deformation bonding that is so-called metal flow. A space is defined between the joint and the module body.

Abstract: A non-transitory computer-readable storage medium has stored therein a material evaluating program. The material evaluating program includes a first program code and a second program code. The first program code causes a computer to evaluate, in units of pages included in a material, an object impression degree for each of all objects included in each of the pages, the object impression degree indicating the strength of an impression made by the object included in the page. The second program code causes the computer to display an evaluation result about the object impression degrees obtained by executing the first program code.

Abstract: A tank pressure transmitter with integrated breathing gas analyzer and associated methods are provided. The tank pressure transmitter can include a gas sensor which detects a constituent of a breathing gas. The transmitter is operable to compile a constituent reading from the constituent detected, and communicate this constituent reading wirelessly to a dive computer.

Abstract: Provided is a pressure detection device including: a pressure sensor including a pressure detection surface for detecting a pressure of a fluid; and a flow channel unit having a flow channel formed therein to guide the fluid to the pressure detection surface. The flow channel unit includes a flow channel body having the flow channel 21a formed therein, and an earth ring disposed in contact with the pressure sensor. The earth ring is formed of a conductive fluororesin material including a fluororesin material and a conductive material in which the fluororesin material is dispersed, and is maintained at a ground potential.

Abstract: A multiple channel control system, pressure detection system, a method and a program are provided. A pressure detection system may include first and second pressure transducers having a common pressure source as an input. The first pressure transducer is a different type than the second pressure transducer. The system also includes a storage device configured to store a look up table having a calibrated relationship between temperature and pressure for the second pressure transducer. The system also includes a processor configured to periodically update the look up table based on pressure detected by the first pressure transducer when a condition is met.

Abstract: A mass simulator to determine unbalance of a rotor module in a balancing machine that simulates the mass of an adjacent rotor module. The mass simulator has a shaft extending along an axis of rotation of the mass simulator. The shaft has an attachment interface at one end for attaching to a corresponding interface, and has a support portion at the opposite end which is rotatably supportable in the balancing machine. The mass simulator has a mass body mounted to the shaft by a release mechanism allowing the mass body to be repeatably mounted to and dismounted from the shaft. The mass simulator being attached to the rotor module at the attachment interface and the assembly of the attached mass simulator and rotor module located in the balancing machine to determine unbalance of the rotor module with the mass body mounted to, and dismounted from, the shaft.

Abstract: There are provided a fluid-path tester and a fluid-path testing-method capable of performing classification of abnormal-modes into a problem in a system, a leakage in a dedicated tube, a problem of a failure in a suppression pressure, and the like, an analysis of the abnormal-modes, and the like in a simplified manner. PAPS valves are included, and an abnormality emulator inspecting an abnormal condition in a fluid path of a DUT by emulating characteristics of the fluid-circuit represented by each of a plurality of abnormal-modes having possibilities of occurring in the fluid path of the DUT through pressurization of a fluid pressure using a compressor-under-test and adjustment of the fluid pressure using the PAPS valves.

Abstract: A semiconductor device may include a semiconductor wafer, and a reference circuit carried by the semiconductor wafer. The reference circuit may include optical DUTs, a first set of photodetectors coupled to outputs of the optical DUTs, an optical splitter coupled to inputs of the optical DUTs, and a second set of photodetectors coupled to the optical splitter. The optical splitter is to be coupled to an optical source and configured to transmit a reference optical signal to the first set of photodetectors via the optical DUTs and the second set of photodetectors.

Abstract: A flexible pipe body comprising an elongate curvature sensor and a tensile armor layer. The elongate curvature sensor incorporates a strain sensor arranged to provide an indication of bending strain applied to the curvature sensor. The tensile armor layer comprises helically wound tensile armor wires. The curvature sensor is positioned within the tensile armor layer helically wound adjacent to at least one tensile armor wire such that bending strain applied to the flexible pipe body is transmitted to the curvature sensor. The curvature sensor is smaller than an adjacent tensile armor wire in at least one of depth and width and arranged to slide longitudinally relative to the adjacent tensile armor wire.

Abstract: Device for inspecting by interferometry the geometry of an end face of a ferrule of a multi-fiber optic connector. The device allows the ferrule to be held by a holder of the ferrule, and a supporting plate including a receiving device adopts a position in space that is mainly conditioned by the interaction of the receiving device of the supporting plate with an engagement device provided on the ferrule. The supporting plate includes a reference surface with respect to which is measured by interferometry the geometry of the end face of the ferrule, the position of this reference surface being preset with respect to the orientations of the receiving device.

Abstract: An optical line testing device for measuring at least a cutting position of an optical line according to the present invention includes: a first wavelength tunable laser source configured to generate a first optical signal in which a plurality of wavelengths appear alternately and periodically; a second wavelength tunable laser source configured to generate a second optical signal which is identical to the first optical signal but has an adjustable delay time; and an interferometer configured to cause interference between a reflected optical signal, corresponding to the first optical signal, which is returning after having been emitted to the optical line, and the second optical signal to output an interference signal.

Abstract: Determining a gear dynamic transmission error may include calculating a collision time interval via parameter values, such as an angular velocity of an input shaft measured by an angle coder, a drag torque of an output shaft provided by a magnetic powder brake, a gear backlash, and angular displacements of the input shaft and the output shaft and comparing a relative displacement contained with the gear backlash, until a value of the relative displacement of the comparison falls within an appropriate interval and meets requirements. In this way, a transmission error with relatively high accuracy may be obtained.

Abstract: Methods and systems are provided for sensing particulate matter by a particulate matter (PM) sensor positioned downstream of a diesel particulate filter in an exhaust system. In one example, a PM sensor assembly may include rows of flow guides separated from each other by a gap where each of the flow guide includes a positive and negative electrode formed on opposite side surfaces. By aligning projections in the gap between successive flow guides, exhaust PM may be circulated in the gap between the electrodes for a longer time, thus increasing the probability of capture across the electrodes, and thereby increasing the sensitivity of the assembly to detection of exhaust PM.

Abstract: Provided is an exhaust flow tube system for use with emissions test equipment, the system comprising: a primary flow tube configured to receive exhaust gases from an engine exhaust pipe and to deliver the exhaust gases to emissions test equipment; a secondary flow tube configured to receive exhaust gases from the engine exhaust pipe and to deliver the exhaust gases to the emissions test equipment; a valve configured to control the flow of exhaust gases through the secondary flow tube; and a control system configured to receive a signal indicative of the flow rate or likely flow rate of exhaust gases from the engine exhaust, and to control the operation of the valve to alter the flow of exhaust gases through the secondary flow tube dependent on the signal.

Abstract: A biological sample collection device 10 is disclosed including a shaped sample collecting tip 20a, said tip at least being formed from a fibrous material mixed with a liquid to form a pulp, said pulp being solidified to form the shape of the tip.

Abstract: The application discloses a device for drawing a liquid from a process tank to be protected from contamination, including: a first receptacle for receiving the liquid withdrawn from the process tank; a first liquid line connecting the process tank with the first receptacle; and at least one first valve assembly disposed in the first liquid line and designed to block or release liquid transport through the first liquid line. The device includes at least one pressure sensor for detecting a pressure within the first receptacle. The device is designed such that a pressure difference between the first and the second ends of the first liquid line is greater than a predetermined minimum value when the first liquid line is connected with the process tank and the process tank is to be protected from contamination.

Abstract: A non-contacting aerodynamic jet tool for collecting particles and vapors associated with surfaces. Opposing planar jets or planar jet arrays are used to liberate material from surfaces so that resuspended particulate matter and vapors can be collected for analysis. In operation, high-speed valves are triggered to create waveforms of high velocity pressurized planar jet bursts. The wall jets that traverse the surfaces exhibit unexpectedly high wall surface stress with velocity spikes characteristic of a chain of shock waves. Unlike axisymmetric jets, the wall jet tool flows over the target surface for a greater distance with wall shear stress having sufficient momentum to dislodge particles submerged in the boundary layer, dramatically improving sampling efficiency by lifting the particles and vapors from the boundary layer into a sampling intake for downstream analysis.

Abstract: A method for deparaffinizing an FFPE tissue sample comprises mixing the FFPE tissue sample with an organic solvent to form a first mixture (10). A surfactant is added to the first mixture (10) to form a second mixture. The second mixture is separated into an organic solvent layer (11) and a surfactant layer (12). The surfactant layer (12) comprises a deparaffinized tissue sample from the FFPE tissue sample. The method also comprises adding water or an aqueous solution to the separated second mixture to form an organic solvent layer (11), a water or aqueous solution layer (13) and a surfactant layer (12). This surfactant layer comprises the deparaffinized tissue sample.

Abstract: The present disclosure provides methods for carrying out Romanowsky-type stains, specifically Wright-Giemsa and May-Grünwald stains, quickly and efficiently. The methods greatly reduce the overall amount of time required to complete a Wright-Giemsa stain or a May-Grünwald stain of sufficient quality on a biological sample. The subject methods can be applied to both manual and automated staining procedures.

Abstract: A method according to the present invention, it is possible to accurately measure the stretch-flangeability of sheet metal materials without size effects even when a small amount of specimen is used, compared with the stretch-flangeability established as an international standard, and to measure the stretch-flangeability in the local region.

Abstract: Embodiments of the invention include a biosensor, such as an implantable biosensor, that includes a sensor material sensitive to at least one analyte in a pressure measurement chamber coupled to a pressure sensor. In embodiments of the invention, a pressure prevailing in the pressure measurement chamber may be determined by the pressure sensor. The sensor material is coupled in the pressure measurement chamber to a compensation material, which includes a relationship between a temperature and a volume of the pressure. The relationship is opposite to a temperature-dependent change in pressure or volume of the sensor material and at least partially compensates for a cross-sensitivity-induced change in volume of the sensor material.

Abstract: A vibratory sensor (5) includes a vibratory element (104), a receiver circuit (134) that receives a vibration signal from the vibratory element (104), and a drive circuit (138) that generates a drive signal. The drive circuit (138) includes a closed-loop drive (143) and an open-loop drive (147). The meter electronics (20) vibrates the vibratory element (104) commencing at a commanded first frequency and in an open-loop manner to achieve a first target phase difference ?1 for a fluid being characterized and determines a corresponding first frequency point ?1, vibrates the vibratory element (104) commencing at a commanded second frequency and in the open-loop manner to achieve a second target phase difference ?2 and determines a corresponding second frequency point ?2, and determines a viscosity of the fluid being characterized using the first frequency point ?1 and the second frequency point ?2.

Abstract: A particle detector that includes a housing defining a chamber, and an air stream injector, producing an airstream with entrained particles, in the chamber. A light source produces a light beam that intersects with and is wider than the air stream. A light detection assembly detects light generated by scattering of the light beam, by particles in the air stream. A digitizer produces a sequence of scattering digital values, each representing light detected per a first unit of time duration. Additionally, a summing assembly produces a sequence of summed scattering digital values, each equaling a sum of a sequential set of n of the digital values, and wherein successive summed digital values are offset by a the first unit of time duration and overlap by n?1 of the first units of time duration with a nearest neighbor. Finally, a detection assembly processes the summed scattering digital values to detect particles.

Abstract: Methods and apparatus are disclosed for measuring the permeability and/or porosity of ultra-low permeable rock samples. In some embodiments, the methods utilize fluid pressure perturbation.

Abstract: Systems and methods evaluate the results produced by histogram segmenting techniques. Exemplary techniques assess boundary region decision or placement techniques according to histogram based metrics, population based metrics, or combinations or transformations thereof.

Abstract: In some aspects, a flow cytometer system is provided that includes beam shaping optics positioned to manipulate a light beam and produce a resulting light beam that irradiates the core stream at the interrogation zone of the flow cell. The beam shaping optics include an acylindrical lens positioned to receive and focus light in a direction of a first axis orthogonal to a direction of light travel, and a cylindrical lens positioned to receive the light output from the acylindrical lens and to focus the light output from the acylindrical lens in a direction of a second axis orthogonal to the first axis and to the direction of light travel. The resulting light beam output has a flat-top shaped intensity profile along the first axis, and a Gaussian-shaped intensity profile along the second axis. Related methods of shaping a light beam at an interrogation zone of a flow cell are also provided.

Abstract: Systems, methods and non-transitory storage medium are disclosed herein for adjusting an output of a particle inspection system representative of a particle characteristic for a particle flowing in a flow-path of a particle processing system. More particularly, the output may be processed and a calibrated output of the particle characteristic generated. In other embodiments, one or more calibration particles are used. Thus, an output of a particle inspection system representative of a particle characteristic for one or more calibration particles flowing in a flow-path of a particle processing system may be compared relative to a standard and an action may be taken based on a result of the comparing the output to the standard.

Abstract: The present invention regards nano surfaces and particularly a gradient based nano surface. According to embodiments of the invention a surface bound gradient is created by distributed nanoparticles along a plane surface. This procedure greatly reduces the number of prepared surfaces needed, as well as the methodological error of analysis of adsorption and adhesion phenomena.

Abstract: A method of preparing specimens for peel-adhesion testing. The method includes applying a first predetermined amount of light-curable material to a substrate coupon, placing a first surface of a substantially transparent peel media in contact with the light-curable material disposed on the substrate coupon, where the substantially transparent peel media includes a second surface spaced from the first surface, and exposing the first predetermined amount of light-curable material disposed between the substrate coupon and the first surface to a light source to cure the first predetermined amount of light-curable material, with light from the light source passing through the substantially transparent peel media to the substrate coupon.

Abstract: The invention relates to installations for fiber optic monitoring of articles, and apparatus and methods for forming such installations, including a modular system and components for forming a fiber optic monitoring installation. Applications of the invention include the monitoring of vessels, chambers, and fluid conduits in industrial processing plants, and the invention has particular application to monitoring large vessels, for example temperature monitoring of vessels used in catalytic reforming processes. Convenient installation on or removal from the article being monitored is achieved by providing a support structure for the fiber optic length, which presents the fiber optic length in a preconfigured orientation suitable for monitoring the article. In a particular embodiment of the invention, the fiber optic length is disposed on a panel in a plurality of dense spiral patterns.

Abstract: A calibration suspension unit has a container made of a flexible material that is filled with a calibration suspension for the calibration of a turbidity meter. There exists no air supernatant above the calibration suspension in the container. Further, a method for the manufacture of a calibration suspension unit is provided and its use for the calibration of a turbidity meter is described.

Abstract: A container (1) has a measuring-cell housing (5) that protrudes into the container interior (2). The measuring-cell housing (5) has a measuring gap (6) bounded by two opposed spaced-apart lateral surfaces (8, 9), and a connecting surface (10) connects the lateral surfaces (8, 9). Each lateral surface (8, 9) has an optical window (11, 12). A first optical fiber (15, 15?) is arranged before the first window (11) and a second optical fiber (17, 17?) is arranged before the second window (12). Receiving channels (14, 16, 18) are arranged before the windows (11, 12, 13) and subsequently can be fit with the optical fibers (15, 15?, 17, 17?, 19) from the outside. The measuring-cell housing (5) having the windows (11, 12, 13) and the receiving channels (14, 16, 18) is connected fixedly to the wall (3) of the container interior (2).

Abstract: A method for obtaining spectral imaging data comprises at least the steps of receiving a sample set of data generated by sampling a spectral property of an image of an object in a spatial basis, wherein the sampling of the spectral property of the image of the object comprises providing a Spectral Filter Array (SFA) by arranging a plurality of SFA elements together to form a surface; configuring each SFA element of the plurality of SFA elements to filter one or more spectral bandwidths centered each at specific wavelengths corresponding to that SFA element, whereby all of the plurality of SFA elements taken together cover a determined spectral range; and setting the specific wavelengths of each SFA element of the plurality of SFA elements on the surface such to obtain a uniform and aperiodic spatial distribution of all of the plurality of SFA elements across the surface.

Abstract: Disclosed herein are embodiments of sensor devices comprising a sensing component able to determine the presence of, detect, and/or quantify detectable species in a variety of environments and applications. The sensing components disclosed herein can comprise MOF materials, plasmonic nanomaterials, redox-active molecules, a metal, or any combinations thereof. In some exemplary embodiments, optical properties of the plasmonic nanomaterials and/or the redox-active molecules combined with MOF materials can be monitored directly to detect analyte species through their impact on external conditions surrounding the material or as a result of charge transfer to and from the plasmonic nanomaterial and/or the redox-active molecule as a result of interactions with the MOF material.

Abstract: The present invention is one adapted to correct the effect of a second gas component on a first gas component in real time even when the concentration of the second gas component as a coexistent component varies every moment, and includes: a first gas analysis part adapted to measure the concentration of the first gas component contained in sample gas; a second gas analysis part adapted to measure the concentration of the second gas component contained in the sample gas; a correction coefficient storage part adapted to store a correction coefficient for correcting the effect of the second gas component on the first gas component; and a concentration correction part adapted to correct the first gas component concentration on the basis of the correction coefficient, the second gas component concentration of calibration gas used for calibrating the first gas analysis part, and the second gas component concentration.

Abstract: The gas detection device according to the present invention is provided with: a first image processing unit for generating a first binary image for indicating in binary fashion the inside and outside of a first region indicating water vapor and a gas to be detected, on the basis of a first image generated using an optical filter having a first pass wavelength band including at least an absorption wavelength band of the gas; a second image processing unit for generating a second binary image indicating in binary fashion the inside and outside of a second region indicating the water vapor, on the basis of a second image generated using an optical filter having a second pass wavelength band different from the absorption wavelength band; and a third image processing unit for calculating a difference between the first binary image and the second binary image.

Abstract: The present invention provides a Voigt line shape fitting method, including step 1: Calculate a Gauss line shape function and a Lorentz line shape function, and calculate a Voigt line shape function. Step 2: For determined line shape parameters to be fitted, calculate partial derivatives of the Voigt line shape function with respect to the parameters, convert a partial derivative of the Voigt line shape function with respect to a parameter into a partial derivative of the Gauss line shape function or the Lorentz line shape function with respect to the parameter. Step 3: Substitute the Voigt line shape function and the partial derivative of the Voigt line shape function with respect to the parameter to be fitted, into a least squares algorithm step, perform least squares fitting calculation, and determine whether to terminate the least squares fitting calculation or return to step 1 to perform next iterative calculation.

Abstract: Contrast enhancement in a metrology tool may include generating a beam of illumination, directing a portion of the generated beam onto a surface of a spatial light modulator (SLM), directing at least a portion of the generated beam incident on the surface of the SLM through an aperture of an aperture stop and onto one or more target structures of one or more samples, and generating a selected illumination pupil function of the illumination transmitted through the aperture utilizing the SLM in order to establish a contrast level of one or more field images of the one or more target structures above a selected contrast threshold, and performing one or more metrology measurements on the one or more target structures utilizing the selected illumination pupil function.

Abstract: An illuminator/collector assembly can deliver incident light to a sample and collect return light returning from the sample. A sensor can measure ray intensities as a function of ray position and ray angle for the collected return light. A ray selector can select a first subset of rays from the collected return light at the sensor that meet a first selection criterion. In some examples, the ray selector can aggregate ray intensities into bins, each bin corresponding to rays in the collected return light that traverse within the sample an estimated optical path length within a respective range of optical path lengths. A characterizer can determine a physical property of the sample, such as absorptivity, based on the ray intensities, ray positions, and ray angles for the first subset of rays. Accounting for variations in optical path length traversed within the sample can improve accuracy.