Abstract: A system configured to emulate a correlithm object processing system includes an input node, a first output node, and a second output node. The input node receives a real-world numeric value comprising an amplitude component and a phase component. The first output node receives the amplitude component and generates a first correlithm object associated with the amplitude component. The second output node receives the phase component and generates a second correlithm object associated with the phase component. A string correlithm object engine maps the first correlithm object to a first sub-string correlithm object of a string correlithm object, and maps the second correlithm object to a second sub-string correlithm object of the string correlithm object.

Abstract: A spherical, self-propelled device responds to remote controls from a user. The self-propelled device has an internal drive system and an internal vision system. The vision system remains in a constant orientation with respect to the spherical, self-propelled device. As the spherical, self-propelled device rolls along a surface, the internal vision system captures video data from an upward field of view.

Abstract: A method of measuring with which it is possible to measure with a high accuracy a gas introducing hole provided in an electrode for a plasma etching device, and to provide an electrode provided with a highly-accurate gas introducing hole is described. This method is provided to penetrate through in the thickness direction of a base material of the electrode for the plasma etching device, provided with: a step of radiating light toward the gas introducing hole from one surface side of the substrate; a step of acquiring a two-dimensional image of light which has passed through the gas introducing hole to the other surface side of the substrate; and a step of measuring at least one of the diameter, the inner wall surface roughness, and the degree of verticality of the gas introducing hole, on the basis of the two dimensional image.

Abstract: A device is provided that measures the variance in ovality, for example, in a pipe, in comparison with a circle. The device will measure, for example, a number of distance points around the outside diameter of a pipe using, in one embodiment, laser distance measuring technology, and optionally using a combination of wireless data transfer including Bluetooth and CAD technology, a series of data points can be generated and plotted. It will then be determined which data points match a circle template, and which do not, with the difference in ovality then being calculated. The device can also measure, through distance measurements, the depth of pits on the exterior surface of a pipe.

Abstract: The invention relates to a method and apparatus for monitoring yarn quality in the textile industry. Textile yarn is checked for quality to meet the required criteria such as diameter evenness and unwanted foreign fiber presence. The invention utilizes an artificial light illuminating the yarn, focusing element, diffraction element and the image sensor for capturing of focused diffracted rays from illuminated yarn image. The presence of foreign fibres in yarn and yarn diameter is determined by processing of captured image.

Abstract: Disclosed are methods and apparatus for inspecting and processing semiconductor wafers. The system includes an edge detection system for receiving each wafer that is to undergo a photolithography process. The edge detection system comprises an illumination channel for directing one or more illumination beams towards a side, top, and bottom edge portion that are within a border region of the wafer. The edge detection system also includes a collection module for collecting and sensing output radiation that is scattered or reflected from the edge portion of the wafer and an analyzer module for locating defects in the edge portion and determining whether each wafer is within specification based on the sensed output radiation for such wafer. The photolithography system is configured for receiving from the edge detection system each wafer that has been found to be within specification. The edge detection system is coupled in-line with the photolithography system.

Abstract: A testing device includes a positioning mechanism, a testing mechanism, and a controller. The testing device is used for testing lengths, widths, straightness, verticality, flatness, position of the testing points, and other dimensions of a workpiece. The positioning mechanism is used for positioning the workpiece. The testing mechanism is fixed on the positioning mechanism for testing dimensions of the workpiece at one time. The controller is electrically coupled to the testing mechanism for controlling the testing mechanism in use.

Abstract: A measurement system includes a signal generator producing an RF modulation frequency and sampling frequency and sending the sampling frequency to an ADC, and sending the RF frequency to modulate a first light source to produce a first light; an optical system sending a portion of the first light to a reference optical detector a portion of the first light out a measurement device to a target that returns a second light to the optical system which sends the second light to a measure optical detector, the reference and measure optical detectors converting the optical signals into corresponding electrical signals; a first ADC channel receiving the electrical measure signal and producing digital measure values; a second ADC channel receiving the electrical reference signal and producing digital reference values; and a processor receiving the digital measure and reference values and calculating the device to target distance.

Abstract: A rugged hand-held mobile computing device for a forester to collect and use dendrometric data from trees and tree stands is claimed. The device includes a processor which operates in connection with a memory, a user interface, a GPS receiver, a sound sensor capable of emitting an ultra-sonic pulse and a computer readable code embodied on the memory. The device communicates with a transponder by way of the ultra-sonic pulse emitted by the sound sensor. The transponder also emits an ultra-sonic pulse back to device. The device calculates the distance traveled based on the knowledge of the speed of the pulses. The memory, which also includes basic mapping software, uses the data to update a map in real time with the location of the trees and other information collected.

Abstract: An inner diameter measuring device, comprising a measurement carriage (2) traveled in straight direction, pipe holding frames (3, 4) disposed at front and rear positions with respect to advancing direction of the measurement carriage and for mounting a pipe to be measured (7), a measuring head (11) supported at a forward end of a supporting member (9) extended in a direction parallel to advancing direction of the measurement carriage, a first laser distance measuring unit (12) and a second laser distance measuring unit (13) disposed in traveling distance of the measurement carriage and for performing distance measurement in two directions perpendicularly crossing to each other, wherein the pipe holding frames can adjust a supporting position of the pipe to be measured as mounted in horizontal direction and in vertical direction, the measuring head measures an inner diameter of the pipe to be measured on condition that the measuring head is inserted in the pipe to be measured, reference outer peripheral surfac

Abstract: Disclosed is an inspection device for inspecting deformation of a substrate holding member of a substrate transport apparatus. The substrate holding member is moved in the forward-and-backward direction relative to the transport base to pass across a light path of the detection light formed by an optical detection unit. The position, with respect to a direction transverse to the forward-and-backward direction, of the substrate holding member is detected based on a detection signal of the optical detection unit. Based on a correlation data expressing the relationship between a first parameter indicative of a change of a position of the substrate holding member with respect to the forward-and-backward direction and a second parameter indicative of the change of the position of the substrate holding member with respect to the direction transverse to the forward-and-backward direction, whether or not deformation occurs in the substrate holding member is judged.

Abstract: In a method of determining the focus of a lithographic apparatus used in a lithographic process on a substrate, the lithographic process is used to form a structure on the substrate, the structure having at least one feature which has an asymmetry in the printed profile which varies as a function of the focus of the lithographic apparatus on the substrate. A first image of the periodic structure is formed and detected while illuminating the structure with a first beam of radiation. The first image is formed using a first part of non-zero order diffracted radiation. A second image of the periodic structure is formed and detected while illuminating the structure with a second beam of radiation. The second image is formed using a second part of the non-zero order diffracted radiation which is symmetrically opposite to the first part in a diffraction spectrum.

Abstract: The present invention provides a method of measuring a width of a color filter unit of a liquid crystal panel. The method includes providing a bottom glass substrate having a TFT array thereon; forming the color filter plate locating within an effective region of the liquid crystal panel by photo-etching process, and forming one or more measure modules locating of the liquid crystal panel and on the TFT array by the photo-etching process; and measuring widths of the one or more measure modules out of the effective region to obtain the width of the filter units within the effective region. The method provided is capable of effectively controlling widths of the color filter units formed in process of manufacturing the liquid crystal panel, thus quality of the liquid crystal panel is raised.

Abstract: A gap measurement device 1 comprises a light source 5 for projecting light on a gap 3 to be measured, a lens optical system 6 for focusing on an imaging surface 7 a gap image 3A from light transmitted through the gap 3, and a light-receiving element 9 for receiving light of the gap image 3A formed on the imaging surface 7 of the lens optical system 6. A holed mask 8 provided with a light-transmitting hole 8a having a prescribed aperture size is arranged on the imaging surface 7, and the light-receiving element 9 receives the light of the gap image 3A via the hole 8a. A gap size at a point to be measured in an extended gap 3 can be measured by forming an image of the gap with the lens optical system 6 and placing the hole 8a of the holed mask 8 on the point to be measured on the imaging surface 7 of the lens optical system 6.

Abstract: The invention relates to a method of measuring the inside diameter of a hollow body (2). According to the invention: the hollow body (2) is illuminated from one side by a diffuse light source (9) presenting two light boundaries (91, 92) that are spaced apart along the measurement axis (x) so as to create two light transitions in an image, which transitions are spaced apart from each other and diametrically opposite; from the side of the hollow body that is opposite from its illuminated side, the light rays that are reflected and refracted by the hollow body (2) are recovered to form at least one image in which there appear at least the two light transitions; and the image is processed in order to determine the distance between the two light transitions in order to determine a measurement for the inside diameter of the hollow body.

Abstract: An optical measuring apparatus includes a light emitter, a scanner, a polarizing plate, a photoreceiver, and a CPU. The light emitter emits a laser beam. The scanner uses the laser beam emitted from the light emitter and scans a measurement region where a work piece is placed. The polarizing plate allows passage for only a laser beam, among the laser beams fired by the scanner, directed orthogonally to an emission direction of the laser beam and an axis direction of the work piece. The photoreceiver receives the laser beam that has passed through the measurement region and the polarizing plate. The CPU calculates a dimension of the work piece from a pattern of light and dark in a scan direction, the pattern being obtained by the photoreceiver.

Abstract: There is provided a component mounting apparatus, which includes: a nozzle which sucks a component; a nozzle supporting member, on which the nozzle is installed, which moves in a vertical direction with respect to an upper surface of a substrate on which the component sucked at the nozzle is mounted; an optical system which captures an image of a leading edge portion of the nozzle where the component is sucked in a component mounting operation, from a side direction, such that an optical axis of the optical system is inclined at a predetermined angle with respect to a sucking surface of the nozzle; and an analyzer which analyzes the image of the leading edge portion to determine whether a sucking state of the component sucked by the nozzle is normal or abnormal.

Abstract: When a label printer detects the paper width, the paper width detection operation scans the transportation path in the paper width direction by the paper width detector not once but twice, and conveys the recording medium transportation distance L, which is longer than the gap length of the gap between labels and is shorter than the label length of each label, between the first and second paper width detection operations. Of the two positions detected as the left edge of the recording medium in the first and second detection operations, the position that is farthest left is used. Likewise, of the two positions detected as the right edge of the recording medium in the first and second detection operations, the position that is farthest right is used.

Abstract: The present invention is to generate a pulsed laser beam having a width greater than the gap between a rotating tool and a workpiece opposed thereto, and then irradiate the gap with the generated laser beam while the optical axis thereof is tilted relative to a workpiece plane. The pulsed laser beam has one lased-pulse period per one revolution or an integer number of revolutions of the rotating tool and is directed in the same angle range relative to the rotating tool within the ON durations of the lased pulse. The light which has irradiated the gap and has not been interrupted but diffracted by the gap is detected on a light-receiving sensor to measure the length of the gap.

Abstract: A method of inspecting a substrate is disclosed. The method of inspecting a substrate, comprises: obtaining phase data per projecting part with regard to a substrate, by projecting pattern beam onto the substrate having a target object formed thereon through a plurality of projecting parts in sequence; obtaining height data per projecting part with regard to the substrate by using the phase data per the projecting part; compensating tilt of the height data by using the height data per projecting part; modifying the tilt-compensated height data per projecting part; and obtaining integrated height data by using the modified height data.

Abstract: A method for determining the rolling radius of a wheel, of a motor vehicle on a road surface, including: projecting a light pattern onto the wheel and road surface; recording a light pattern reflected by the wheel and road surface using an image recording device; determining 3D coordinates of points of the reflected light pattern; identifying points of the reflected light pattern of the wheel; identifying points of the reflected light pattern of the road surface; determining the position of the center of rotation of the wheel from the reflected light pattern points identified as belonging to the wheel; determining the position of the road surface from the reflected light pattern points identified as belonging to the road surface; determining the rolling radius on the contact surface of the wheel as the distance between the center of rotation of the wheel and the position of the road surface.

Abstract: A diameter sensing assembly is provided for determining the location of a change in diameter in a pipe from a remote location outside of the pipe. The assembly includes an imaging device operatively connected to an imaging cable and a diameter sensing device operatively connected to a sensing cable. The sensing device is positioned generally forward of the imaging device, and includes a plurality of flexible arms that are rigid enough to stay horizontal, but flexible enough to bend or depress easily. The two cables are connected to one another such that the entire assembly is able to be moved through a pipe at a constant speed. Marks are placed on one of the cables to determine the length to the change in diameter, and the length of portions of pipes having different diameters.

Abstract: An apparatus and method for determining the diameter of a pipe from a remote location is disclosed. A measuring assembly, including a reference device and an imaging device, is inserted into a pipe from a remote location. The reference device is inflatable to a predetermined and known diameter within the pipe. The imaging device acquires imaging data of the reference device within the pipe and the imaging data is used to determine the diameter of the pipe by comparing the predetermined diameter of the reference device with the diameter of the wall of the pipe. The diameter of the pipe is then used to properly choose a liner assembly of the same diameter to repair the wall of the pipe. The liner tube may include a bladder and liner tube, which is saturated with a curable resin, to repair the wall of the pipe.

Abstract: A method for determining the rolling radius of a wheel, of a motor vehicle on a road surface, including: projecting a light pattern onto the wheel and road surface; recording a light pattern reflected by the wheel and road surface using an image recording device; determining 3D coordinates of points of the reflected light pattern; identifying points of the reflected light pattern of the wheel; identifying points of the reflected light pattern of the road surface; determining the position of the center of rotation of the wheel from the reflected light pattern points identified as belonging to the wheel; determining the position of the road surface from the reflected light pattern points identified as belonging to the road surface; determining the rolling radius on the contact surface of the wheel as the distance between the center of rotation of the wheel and the position of the road surface.

Abstract: A measurement system comprising an elongated member, a distal member connected to an end of the elongated member, the distal member having one or more register members to define a reference point(s), and a beam measurement device mounted to the distal member and configured to generate a beam at least a portion of the beam having a first axis essentially perpendicular to the reference point(s), the beam measurement device determining distance data based on the reflection of at least a portion of the beam.

Abstract: An original document size detection device of the present invention is characterized by comprising a document reading table, a light source which irradiates an original document placed on the document reading table, a cover body which covers the original document, a light detection unit which detects a reflected light that a light from the light source is reflected by the original document and an external light that enters the surface of the document reading table when the cover body is lifted, a masking unit which masks an output signal based on the external light in the output signal of the light detection unit based on the reflected light and the external light, and a determination unit which determines a size of the original document in a main scanning direction based on the output signal of the light detection unit that is masked by the masking unit.

Abstract: An apparatus and method for inspecting a graphene board. The graphene board inspecting apparatus for inspecting a graphene board on which at least one graphene layer is formed includes: a light processing unit which emits at least one light on the graphene board, receives the at least one light penetrating the graphene board and converts the received at least one light to an output signal; a transmittance detecting unit which receives the output signal from the light processing unit to inspect a transmittance of the at least one light penetrating the graphene board; and a determination unit which is connected to the transmittance detecting unit and receives the detected transmittance to determine a state of the graphene board by analyzing the detected transmittance.

Abstract: A method for inspecting the width of a coated film in accordance with the present disclosure is a method for detecting a width W1 of a coated film 20, the method including: a step of measuring a thickness profile in the transverse direction of the coated film 20; a step of creating approximating curves L1, L2 of a function of a distance X and a thickness Y in end-proximal regions 24a, 24b of both ends of the coated film 20; and a step of taking a distance Xe1 corresponding to a thickness threshold Yt determined from the approximating curve L1 of one end-proximal region 24a and a distance Xe2 corresponding to the thickness threshold Yt determined from the approximating curve L2 of the other end-proximal region 24b, and of calculating Xe1?Xe2 as the width W1.

Abstract: Gaps between strips of composite tape forming a surface are measured by a gauge. The position of the edges of adjacent strips of the tape is sensed as the gauge is moved along the surface, and a gap between the adjacent strips is calculated based on the sensed position of the edges.

Abstract: An original document size detection device of the present invention is characterized by comprising a document reading table, a light source which irradiates an original document placed on the document reading table, a cover body which covers the original document, a light detection unit which detects a reflected light that a light from the light source is reflected by the original document and an external light that enters the surface of the document reading table when the cover body is lifted, a masking unit which masks an output signal based on the external light in the output signal of the light detection unit based on the reflected light and the external light, and a determination unit which determines a size of the original document in a main scanning direction based on the output signal of the light detection unit that is masked by the masking unit.

Abstract: Methods and systems for monitoring semiconductor fabrication processes are provided. A system may include a stage configured to support a specimen and coupled to a measurement device. The measurement device may include an illumination system and a detection system. The illumination system and the detection system may be configured such that the system may be configured to determine multiple properties of the specimen. For example, the system may be configured to determine multiple properties of a specimen including: but not limited to, critical dimension and overlay misregistration; defects and thin film characteristics; critical dimension and defects; critical dimension and thin film characteristics; critical dimension, thin film characteristics and defects; macro defects and micro defects; flatness, thin film characteristics and defects; overlay misregistration and flatness; an implant characteristic and defects; and adhesion and thickness.

Abstract: A computer-implemented method includes receiving a sequence of current spectra of reflected light from a substrate; comparing each current spectrum from the sequence of current spectra to a plurality of reference spectra from a reference spectra library to generate a sequence of best-match reference spectra; determining a goodness of fit for the sequence of best-match reference spectra; and determining at least one of whether to adjust a polishing rate or an adjustment for the polishing rate, based on the goodness of fit.

Abstract: Methods of optimizing the diameters of nanowire photodiode light sensors. The method includes comparing the response of nanowire photodiode pixels having predetermined diameters with standard spectral response curves and determining the difference between the spectral response of the photodiode pixels and the standard spectral response curves. Also included are nanowire photodiode light sensors with optimized nanowire diameters and methods of scene reconstruction.

Abstract: A non-contacting aligning method for planes in a three-dimensional environment is disclosed. The method includes: projecting a light beam in a predetermined incident angle onto a transparent first object and an opaque second object that are facing each other; and calculating a distance between the first and second objects basing on the tangent trigonometric function of the incident angle of the light beam.

Abstract: Apparatus is provided for slitting composite material int1aaaaaaaaaaao tape and for measuring the width of the slit tape as the tape is being reeled onto take up rolls. The tape width is measured by an optical micrometer. The optical micrometer includes a transmitter for directing radiant energy over the tape and, a receiver for receiving radiant energy from the transmitter that passes across an edge of the tape and for producing a signal related to the width of the tape.

Abstract: A disclosed measurement head includes a sensor body attached to a camera by a resilient member. The sensor body includes a sensor that measures linear distance and is actuated by arms pivoting outward from the sensor body into contact with an interior surface of pipe for measurement. Each of the arms includes a catch engageable to a latch sleeve to hold each of the arms in a compact folded position for insertion into a pipe. The latch sleeve is movable to release the catch and the arms to provide for measurement of the interior profile of the pipe. Another measurement head includes guide wires attached to an end of each of the arms. The guide wires provide for movement of the arms to provide for insertion of the measurement head into and through a pipe.

Abstract: A device and method can optically detect a defect of a round wire rod to be tested, and particularly, remotely detect the defect without contact in real-time. The device includes a lighting device for emitting circular surface light to the round wire rod; an optical sensor for generating an optical signal by receiving the light reflected from the round wire rod, which is being transported, and converting the optical signal into an image signal; and a signal-processing unit for acquiring surface information of the round wire rod by receiving the image signal from the optical sensor.

Abstract: A measurement system comprising an elongated member, a distal member connected to an end of the elongated member, the distal member having one or more register members to define a reference point(s), and a beam measurement device mounted to the distal member and configured to generate a beam at least a portion of the beam having a first axis essentially perpendicular to the reference point(s), the beam measurement device determining distance data based on the reflection of at least a portion of the beam.

Abstract: An object detecting device for detecting the existence and general placement of an object residing upon a surface. A preferred embodiment of the invention uses at least one laser measuring scanner operated positioned by a servo motor to allow the laser measuring scanner to generate signals related to the placement of an object on a surface. Those placement signals are then processed by a computer to make a two or three dimensional determination of the object in coordinates that show the object's location in relation to another device such as a robotic depalletizer that can then be moved into position near the object to allow removal of the object by the robotic depalletizer.

Abstract: The invention relates to a device (1) for measuring the width (B) and/or the position of a metal strip (2) or a slab, which has at least two measuring systems (3, 4), with each located on a side (5, 6) of the metal strip (2) or the slab, wherein each measuring system (3, 4) has a sensor (7) designed to detect the lateral end (8, 9) of the metal strip (2). To make the measuring device robust and to enable dynamic measurement, according to the invention the sensor (7) is located on a moving element (10) with which it can be moved in a straight line in a direction (Q) at right angles to the longitudinal direction (L) of the metal strip (2).

Abstract: The present invention is a device to measure the characteristics of droplets within a stream of liquid droplets used in spraying. It comprises: a light source (45) supplying light across the stream of droplets; detection (means 2) to detect change in the light level caused by a passing droplet, the detection means generating a signal according to the change in light; and processing means (59) to analyse the characteristics of the droplets in the stream based on the signal produced by the detection means. The light passes through a slit (3A) in a panel (53) disposed between the droplet stream and the detection means (52), so that the change in level of light detected by the detection means is proportional to the diameter of the droplet. Preferably two or more intersecting light beams (68,69) are used to provide comparative data about passing droplets.

Abstract: An apparatus and a method for ascertaining a gap between a stationary member and a rotating member are disclosed. At least a reference beam and a signal beam, which have different focal lengths or which diverge/converge at different rates, are fixed to the stationary member and proximate to each other. The beams are projected across a gap between the stationary member and the rotating member toward the rotating member. The reference and signal beams are reflected by the translating member when it intersects the reference and signal beam, and the reflected reference and signal pulses are obtained. One or more features of the reflected reference pulse and the reflected signal pulse, such as a rise time of the pulses, a fall time of the pulses, a width of the pulses and a delay between the reflected reference pulse and the reflected signal pulse, among other factors, are obtained. The width of the gap is obtained using at least one of these factors.

Abstract: The invention relates to a method and arrangement for measuring a timber piece (4) in a wood handling machine (1). Such a wood handling machine comprises booms (2) arranged in a base machine and a wood handling device (3) operating therein. In such a wood handling machine (1), a wood handling device (3) grips the timber piece (4) to be handled, after which one end of the timber piece is guided into a measuring carriage (5) in the wood handling machine by the wood handling device. The timber piece arranged in the measuring carriage is subjected to one or more observation measures by observation means provided in the measuring carriage.

Abstract: In order to be able to measure a diameter in a turning machine without rotating a workpiece and thus prevent circularity and concentricity errors from entering into the diameter determination, it is proposed according to the invention to use a measuring device that is movable in both transversal directions relative to the rotation axis, thus in the X-direction and also in the Y-direction, wherein the measuring device can scan the workpiece from both sides in one clamping step without rotating the workpiece.

Abstract: A sheet measurement apparatus has a sheet disposed in a melt. The measurement system uses a beam to determine a dimension of the sheet. This dimension may be, for example, height or width. The beam may be, for example, collimated light, a laser, x-rays, or gamma rays. The production of the sheet may be altered based on the measurements.

Abstract: A method is described for measuring a dimension on a substrate, wherein a target pattern is provided with a nominal characteristic dimension that repeats at a primary pitch of period P, and has a pre-determined variation orthogonal to the primary direction. The target pattern formed on the substrate is then illuminated so that at least one non-zero diffracted order is detected. The response of the non-zero diffracted order to variation in the printed characteristic dimension relative to nominal is used to determine the dimension of interest, such as critical dimension or overlay, on the substrate. An apparatus for performing the method of the present invention includes an illumination source, a detector for detecting a non-zero diffracted order, and means for positioning the source relative to the target so that one or more non-zero diffracted orders from the target are detected at the detector.

Abstract: Provided herein are methods for imaging subwavelength structures in three dimensions and with high resolution. The methods comprise illuminating subwavelength structures with an illuminating wavelength of light and detecting the self-image generated thereby at a distance distal to the structures. Also provided is a method for confining propagating light to a sub-diffraction limit dimension by illuminating a surface of a metal structure with subwavelength features with a wavelength of coherent light such that light propagating from the features is confined to a dimension that is a sub-diffraction limit thereof.

Abstract: Screening methods are provided for identifying pharmacologic inhibitors of HCV amphipathic helix (AH) function, which inhibitors are useful in the prevention and treatment of HCV infection. Also provided are compounds useful in the inhibition of viral replication. The methods of the invention are based on the unexpected discovery that the presence of an AH, e.g. an AH of an HCV polypeptide, causes an increase in the apparent diameter of the vesicles. The methods of the invention provide for addition of AH peptides to lipid vesicles, for example in a high-throughput format; which addition may be performed in the absence or presence of a candidate pharmacologic agent. The change in apparent vesicle size is measured, and compared to control samples. An increase in vesicle size or aggregation is indicative of AH function being present; and a lack of increase is indicative that the AH function is absent or has been inhibited by a test agent.

Abstract: Systems and methods are provided for measuring the thickness of a film on an interior surface of an exhaust pipe system of a vehicle. The film is typically a layer of a nitrogen-oxides reductant, such as urea, deposited during operation of a selective catalytic reduction system for eliminating pollutants in an exhaust stream. The methods and systems are directed to optical measurements that directly probe the interior surfaces of the exhaust system to determine the thickness of a urea film built up during operation of the engine and the selective catalytic reduction system.

Abstract: Disclosed are methods and apparatus for inspecting a sub-resolution assist features (SRAF) on a reticle. A test flux measurement for a boundary area that encompasses a width and a length portion of a test SRAF is determined, and at least one reference flux measurement for one or more boundary areas of one or more reference SRAF's is determined. The test flux measurement is compared with the reference flux measurements. The comparison is used to then determine whether the test SRAF is undersized or oversized. If the test SRAF is determined to be oversized, it may then be determined whether the test SRAF is defective based on the comparison using a first threshold.