Abstract: A method and system for dynamic locating of a fault observed in a defective component related to a forging operation, in which: a processor models a shaping operation of a component by forging, as per a set of successive models of the component; a processor adds a fault plotter to a first model of the set of models, in a zone corresponding to a region of the fault in the defective component to obtain a first plotted model; and a processor tracks the plotter in time from the first plotted model during the modelling to locate an origin of the fault.

Abstract: A test set-up (10) for non-destructive detection of a flaw in a device being tested by means of an eddy current has an excitation coil (14), to which an excitation signal (SE) can be sent to act on the device being tested (16) with an electromagnetic alternating field, a receiving coil (17) to generate a coil signal (SP), which is a function of the flaw in the device being tested (16), an analog-digital converter (21), which is coupled to the receiving coil (17) on the input side, a filter arrangement (22), which is coupled to the analog-digital converter (21) on the input side and is designed for band-pass filtering and scan rate reduction, and a demodulator (27), which is coupled to an output of the filter arrangement (22) on the input side.

Abstract: A tool abnormality detection system corrects a monitoring range for a load on a tool in an Mth cycle by using load data of at least one of 1st to (M?1)th cycles (where M is an integer of 2 or more), wherein processing work on a single workpiece corresponds to a single cycle, and the load data is data about the load on the tool in the cycle.

Abstract: A system and method for detecting and evaluating structural defects are provided. Baseline data representative of sensed ultrasonic waves that were transmitting into a structure with no defects are stored. Ultrasonic waves are transmitted into the structure from a plurality of actuators that are coupled to the structure. The ultrasonic waves that are transmitted into the structure from the plurality of actuators are sensed, with a plurality of sensors that are coupled to the structure and spaced apart from the actuators, to thereby generate and supply sensor data. Signal difference coefficients are calculated from the baseline data and the sensor data. The calculated signal difference coefficients are spatially mapped to detect one or more structural defects in the structure.

Abstract: The system for mitigating an overspeeding condition of a turbine engine can include a sensor for measuring an actual speed of a gas generator turbine of the turbine engine and a processor for deriving a delta, the delta being a comparison between the actual speed of the gas generator turbine and a predicted gas generator turbine speed. The system is configured for detecting the overspeeding condition when delta is higher than a predetermined threshold. A method of detecting an overspeeding condition during operation of a turbine engine can include measuring an actual speed of a gas generator turbine, then evaluating a delta between the actual speed of the gas generator turbine and a predicted speed of the gas generator turbine, then comparing the delta to a threshold value.

Abstract: A non-destructive inspection system that has particular application for inspecting a bore in a valve for defects. The system includes an inspection yoke having a ferromagnetic core, where a first coil is wound around the core in one direction and a second coil is wound around the core in an orthogonal direction so that orthogonal electromagnetic fields can be generated within the bore. A controller provides a current flow through the coils to generate the electromagnetic fields to detect defects in the bore.

Abstract: A simple, inexpensive, and fast method of establishing if a defect does or does not exist within a thick-walled solid geometry, which is especially useful to detect if such a defect, a crack, exists within a gun barrel. With further analysis, the method allows not only the identification of the defect's presence; but, a means of establishing the size thereof—which, for example, is critical to understanding if a gun tube has a defect that would warrant its being taken out of service for the safety of its crew or removed from manufacturing. The method involves creating an acoustic vibration in the particular thick-walled, solid geometry, esp. a gun barrel, and observing the vibration pattern which results.

Abstract: A method for operating a gas turbine engine includes coupling at least one sensor within the gas turbine engine to transmit a signal indicative of a vibration level of a rotor assembly within the gas turbine engine, detecting the vibration level of the rotor assembly based on the signal transmitted from the at least one sensor, comparing the detected vibration level to a predetermined vibration threshold, and generating an output if the detected vibration amplitude exceeds the threshold amplitude for a predetermined duration to facilitate identifying a gas turbine engine impulse event.

Abstract: An apparatus for tuning a parameter of a Kalman filter in a wheel inspection for a vehicle is disclosed. The apparatus includes an association module that associates wheel inspection data of the vehicle with locations of corresponding wheels in the vehicle; an evaluation module that evaluates a wheel stable score of the vehicle based on the wheel inspection data and the association, where the wheel stable score indicates reliability of the wheel inspection; and a parameter tuning module that tunes a measurement error covariance of the Kalman filter according to the evaluated wheel stable score.

Abstract: Provided are an apparatus and method of monitoring a wind turbine blade. The method includes converting strain of a blade into moment, generating a reference value based on design information of the blade and statistical information of the moment, and comparing the moment with the reference value and determining a state of the blade. Accordingly, since the reference value serving as a reference of blade state determination is generated according to blade design information and moment statistical information and learning of the moment statistical information is performed, reliability of blade state determination can be improved, and thus, effective management and maintenance of the blade becomes possible.

Abstract: A method for predicting faults in an aircraft thrust reverser system, the method includes receiving a position signal, determining a variation in the position signal relative to a reference position, predicting a fault in the thrust reverser based on the variation, and providing an indication of the predicted fault.

Abstract: A measurement system scans the given surface of a tire component (e.g., a brush-finished tread or buffed tire casing) to electronically measure data points corresponding to vertical and horizontal coordinates along the given surface. Associated computer processors electronically calculate the slope at a plurality of different locations by determining the degree of steepness (e.g., rise over run, angle or grade) between selected ones of the first and second coordinates and electronically comparing at least one slope-based parameter to one or more predetermined levels to determine a characterization defining one or more of surface adhesion fitness, finishing brush wear level and brush bristle placement location. Slope may be determined between every adjacent pair of data points or between selected data points (e.g., identified local maximum and minimum). The at least one-slope based parameter compared to the predetermined levels may correspond to the slopes themselves or to a calculated average slope value.

Abstract: A method and apparatus for three-dimensional (3D) visualization and analysis for automatic non-destructive examination of a rotor bore using ultrasound. Data is acquired by scanning the rotor bore with an ultrasound pulser/transducer producing a plurality of one-dimensional ultrasound scans, each scan having a plurality of sample points. Each sample point is associated with a voxel of a regular 3D grid having a plurality of voxels. A Gaussian kernel is associated with each sample point and a value for a particular voxel is determined based on a weighted sum of sample points whose kernels cover the particular voxel. The values for the other voxels of the regular 3D grid are determined similarly. A 3D visualization of the rotor bore can be displayed to a user.

Abstract: A method for detecting a fault in a robot joint includes the steps of: performing a first torque measurement at the robot joint to thereby obtain a first set of torque values; calculating a first distribution characteristic reflecting a distribution of the first set of torque values; performing a second torque measurement at the robot joint to thereby obtain a second set of torque values; calculating a second distribution characteristic reflecting a distribution of the second set of torque values; and comparing the first and the second distribution characteristics to determine whether a fault is present or not. A difference in the distributions of torque measurements is a robust fault indicator that makes use of the repetitive behavior of the system.

Abstract: A device is disclosed for performing non-destructive inspection and testing (NDT/NDI) of an elongated test object, wherein the inspection system includes: a test object conveyor for conveying the test object along a longitudinal conveyance path; a probe assembly including phased-array probes, the probe assembly being configured to induce signals in the test object and sense echoes reflected from the test object; a probe assembly conveyor configured to movably support the probe assembly, to move the probe assembly on a circumferential path about the test object; and a control system coupled to the test object conveyor and to the probe assembly conveyor and configured to allow data acquisition by and from the phased-array probes while, simultaneously, the test object moves along the longitudinal path and the phased-array probes move on the circumferential path.

Abstract: A monitoring system includes a testing apparatus and a display control apparatus connected to the testing apparatus. The testing apparatus includes a plurality of testing locations and a collection module connected to the plurality of testing locations. Each of the plurality of testing locations receives a tested product, which is tested by the testing apparatus. The collection module collects testing states of the tested products. A display apparatus is connected to the display control apparatus. The display control apparatus controls the display apparatus to show a plurality of indicating blocks corresponding to the plurality of testing locations. The display apparatus is adapted to display the plurality of indicating blocks to match the plurality of testing locations. The display control apparatus controls each of the plurality of indicating blocks to show the testing state of the tested product in each the plurality of testing locations.

Abstract: An apparatus comprises an inspection vehicle, a sensor system, a positioning system, a controller, and a support system. The inspection vehicle is configured to move on a surface of an object. The sensor system is associated with the inspection vehicle and is configured to generate information about the object when the inspection vehicle is on the surface of the object. The positioning system is configured to determine a location of the inspection vehicle on the object. The controller is configured to control movement of the inspection vehicle using the positioning system and control operation of the sensor system. The support system is connected to the inspection vehicle and is configured to support the inspection vehicle in response to an undesired release of the inspection vehicle from the surface of the object.

Abstract: The present invention provides an optical inspection method capable of detecting a finer defect in the surface of a substrate, including the steps of: irradiating a surface of a sample which is rotating and continuously moving in one direction with illumination light which is incident in a direction obliquely to the sample surface; detecting an image of light formed by a forward scattering light around an optical axis of regular-reflection light while excluding the regular-reflection light from the sample surface irradiated with the illumination light; condensing and detecting lateral scattering light which scatters laterally from the sample surface with respect to an incidence direction of the illumination light; and processing a signal obtained by detecting the image of light formed by the forward scattering light and a signal obtained by condensing and detecting the lateral scattering light to extract a defect including a scratch defect.

Abstract: A method for detecting defect in a weld seam during laser welding. The method includes performing a two-dimensionally locally resolved detection of radiation that is emitted by a solidified molten mass that is adjacent to a liquid melting bath. The method also includes determining at least one characteristic value for heat dissipation in the solidified molten mass by evaluating the detected radiation along at least one profile-section of the solidified molten mass, and detecting a defect in the weld seam by comparing the at least one characteristic value with at least one reference value.

Abstract: A heat tube inspection cable and a method of analyzing an insertion force of the cable are disclosed. The heat tube inspection cable includes a sensor unit configured to detect a defect in a heat tube, a plurality of segment units each configured to comprise a body part and a wheel part rotatably connected to the body part, a signal cable configured to helically pass through the body part of each of the plurality of segment units to transmit electric signal from the sensor unit, and a wire configured to pass through the body part of each of the plurality of segment units to keep the linear configuration of the plurality of segment units like a bead necklace and to provide axial and bending strength.

Abstract: The claimed method and system identifies faults and/or deterioration of components in a process control valve. The system may use different sensor combinations to provide the necessary data to compute irregular component integrity. Alerts may be generated to indicate potential component integrity problems. In particular, the system may detect potential deterioration and/or faults in actuator springs, pneumatic tubing and piping, and bellows seals. The claimed system may be communicatively coupled to a process control network to provide a more elaborate alarm system. Moreover, additional statistical methods may be used to refine the detection accuracy of the system.

Abstract: A method, device and assistance system for detecting leaks in an area of a supply network, wherein leaks are detected by comparing real measured values supplied by sensors with measured values ascertained using a Monte Carlo simulation and, in particular, the method ascertains irregularities, which can be attributed to anomalies such as leaks, based on a hydraulic analysis so that existing leaks can be detected. Furthermore, the method can be applied to sensors that are temporarily installed in the network, giving the network operator additional freedom in the leak detection, and can be used for other supply networks and infrastructures.

Abstract: A self-calibrating magnetic field monitor is disclosed. In one embodiment, a magnetic field sensor repeatedly generates an electronic signal related to the magnetic field. In addition, a calibration module generates a relative baseline signal based on an average value of the electronic signals for a given time period. A comparator compares the electronic signal with the relative baseline signal and generating an output signal if a difference in the comparing is greater than or equal to a threshold.

Abstract: A correlation is preliminarily obtained between a depth of damage and a ratio between a temperature gradient in temperature distribution on a surface of an area containing the damage and a temperature difference between a maximum temperature and a minimum temperature in the temperature distribution. The temperature distribution on the surface of the area containing the damage in the structure is then measured. Once the temperature distribution on the structure surface is obtained, attention is focused on temperature distribution between two points including the damaged area, so that a temperature difference between a maximum temperature and a minimum temperature in the distribution is obtained, and further a temperature gradient of an interval exhibiting temperature variation equal to or higher than a predetermined level is obtained.

Abstract: The prognostic tool disclosed here decomposes the problem of estimating the remaining useful life (RUL) of a component or sub-system into two separate regression problems: the feature-to-damage mapping and the operational conditions-to-damage-rate mapping. These maps are initially generated in off-line mode. One or more regression algorithms are used to generate each of these maps from measurements (and features derived from these), operational conditions, and ground truth information. This decomposition technique allows for the explicit quantification and management of different sources of uncertainty present in the process. Next, the maps are used in an on-line mode where run-time data (sensor measurements and operational conditions) are used in conjunction with the maps generated in off-line mode to estimate both current damage state as well as future damage accumulation.

Abstract: A linear actuator comprises a reversible electric motor (2) which, via a transmission, is capable of driving a spindle (4) having a spindle nut (5) secured against rotation and comprises a power supply and a controller. The actuator moreover comprises a memory unit for collecting at least one set of data from the operation, indicating how long and how hard the actuator has worked. It is hereby possible to obtain an overview of the mechanical state of the actuator and thereby prevent unfortunate occurrences and accidents as a consequence of wear-out of the actuator.

Abstract: The system for mitigating an overspeeding condition of a turbine engine can include a sensor for measuring an actual speed of a gas generator turbine of the turbine engine and a processor for deriving a delta, the delta being a comparison between the actual speed of the gas generator turbine and a predicted gas generator turbine speed. The system is configured for detecting the overspeeding condition when delta is higher than a predetermined threshold. A method of detecting an overspeeding condition during operation of a turbine engine can include measuring an actual speed of a gas generator turbine, then evaluating a delta between the actual speed of the gas generator turbine and a predicted speed of the gas generator turbine, then comparing the delta to a threshold value.

Abstract: A method for monitoring the health of one or more blades is presented. The method includes the steps of generating a signal representative of delta times of arrival corresponding to the rotating blade, generating a reconstructed signal by decomposing the signal representative of the delta times of arrival utilizing a multi-resolution analysis technique, wherein the reconstructed signal is representative of at least one of static deflection and dynamic deflection in the rotating blade.

Abstract: A defect detection system and method enable a fastened crystalline silicon product to generate micro-vibration by a micro-vibration excitation device, so as to enable the crystalline silicon product to generate an excitation signal, then to acquire the excitation signal by a acquisition device, so as to analyze the excitation signal acquired by the acquisition device in the time and frequency domain by an analysis detection device with a specific analysis, and to obtain an analysis result, at last, determine a defect state of the crystalline silicon product according to the analysis result.

Abstract: A probabilistic estimation of fatigue crack life of a component is provided. A plurality of representations of the component is defined from material property scatter data and flaw-size scatter data, wherein each representation is defined by one possible material condition and flaw-size condition associated with the component. For each representation, a component location is selected and a determination is made whether said individual representation fails after a given number of cycles N, based on the calculation of a crack growth in the selected location. The crack growth is calculated on the basis of the material condition and the flaw-size condition in the selected location. Failure of the individual representation is determined if the crack growth is determined to be unstable. The sum total of the number of the representations that failed after N cycles is determined. A probability of failure of the component after N cycles is then determined.

Abstract: A variable speed switch includes a switch main body portion which is accommodated in a housing of an electric power tool and mounted to the housing so as to be capable of relative movement, and a load sensor which is provided in the switch main body portion and capable of outputting an electric signal in proportion to the amount of distortion caused by a pressing force. The switch operating portion is mounted on the surface of the housing so as to be capable of relative displacement with respect to the housing and transmits a pressing force applied to the switch operating portion to the load sensor, with the maximum displacement amount of the switch operating portion being set to equal to or less than 5 mm.

Abstract: A multi-frequency bond-testing system using acoustic probes in conjunction with NDT/NDI inspection instruments. Bond-testing of test objects is carried out at multiple discrete frequencies to produce a single, combined amplitude C-scan. Alternatively, or in combination, the system provides a single, combined phase C-scan to enable proper interpretation of the C-scans. Amplitude and/or phase readings on test objects are normalized at the selected frequencies relative to tests performed on a defect-free object at those frequencies. In this manner, the non-linear behavior of a bond-testing probe over a frequency range chosen for a given inspection is compensated for. The invention enables providing more easily interpretable and sharper images which enable a more reliable and faster reading and identification of defects in the test objects.

Abstract: A method and apparatus are present for monitoring a structure. A signal is sent into the structure, wherein the signal has a limited duration and a varying frequency. A response to the signal is received and the response is compared to a baseline to form a comparison.

Abstract: A method for tuning a parameter of a Kalman filter in a wheel inspection for a vehicle. The method includes: associating wheel inspection data of the vehicle with locations of wheels in the vehicle; evaluating a wheel stable score of the vehicle based on the wheel inspection data and the association, wherein the wheel stable score indicates reliability of the wheel inspection; and tuning measurement error covariance of the Kalman filter according to the evaluated wheel stable score. By using the method, the parameter of the Kalman filter can be dynamically tuned to enable the Kalman filter to filter more accurately to ensure the correct result of the wheel inspection. In addition, an apparatus for tuning a parameter of a Kalman filter and a wheel inspection system for a vehicle are disclosed.

Abstract: Embodiments of the present invention provide systems, methods, and computer medium having computer programs to determine presence of stress corrosion cracking in one or more pipelines or portions thereof such as pipeline joints by utilizing pattern recognition in pipeline data such as magnetic flux leakage data. A screening process, for example, does not affect or change how survey data is recorded such as in survey tools; only how it is analyzed after the survey data is completed. Embodiments of the systems, methods, and computer medium having computer programs can be used to screen for potential locations of stress corrosion cracking in one or more pipelines so that site excavation can occur for confirmation and validation of the output results.

Abstract: A method to enable wafer result prediction includes collecting manufacturing data from various semiconductor manufacturing tools and metrology tools; choosing key parameters using an autokey method based on the manufacturing data; building a virtual metrology based on the key parameters; and predicting wafer results using the virtual metrology.

Abstract: A method for monitoring the health of a plurality of blades is presented. The method includes determining delta TOAs corresponding to the plurality of blades, determining a standard deviation utilizing the delta TOAs corresponding to the plurality of blades, determining a delta sigma—1 utilizing the standard deviation and an initial standard deviation, determining a normalized delta TOA corresponding to one or more of the plurality of blades utilizing the delta sigma—1, determining a standard deviation of the normalized delta TOA, determining a delta sigma—2 utilizing the standard deviation of the normalized delta TOA and a previous standard deviation of normalized delta TOA, and determining a corrected delta TOA corresponding to the one or more of the plurality of blades based upon the delta sigma—2.

Abstract: A fault diagnostic method for an automatic transmission may include monitoring an operating state of a trim system configured to selectively supply clutch engagement pressure and exhaust to at least one clutch control valve, determining an expected operating state of the trim system based on current operating conditions of the transmission, and generating a fault signal if the monitored operating state of the trim system is different from the expected operating state of the trim system.

Abstract: A method and system (20) is provided for condition based monitoring reliability maintenance capabilities for an asset (70), such as one or more machines, by establishing a network including of a sensor (60) or a plurality of sensors installed, temporarily or in generally fixed locations, on asset (70), wherein sensor (60) provides time sequenced operational information in the form of data based on vibrations, temperature, electrical signals, or other operating conditions. Sensors (60) are connected to a local controller (40) which transmits the data via a local or wide area network (45), either through wired or wireless communication paths, in data packets, each containing divided portions of the operational information. The data packets are mapped and stored into multiple, dedicated databases for ease of retrieving and analyzing the data. Preferably, a cloud-based storage arrangement (120) is employed to storing the mapped data.

Abstract: A method is implemented in a computer infrastructure having computer executable code tangibly embodied on a computer readable storage medium having programming instructions. The programming instructions are operable to receive data including code inspection services defect analysis data of a software development project and process the data. Additionally, the programming instructions are operable to determine one or more business metrics based on the data and generate at least one report based on the one or more business metrics.

Abstract: A machine includes a machine body and a dual fuel compression ignition engine attached to the machine body. A dual fuel system is operably coupled to supply the engine with liquid diesel fuel and natural gas fuel directly into respective cylinders of the engine. The fuel system includes an insulated tank for storing the natural gas fuel, a pressure sensor positioned to measure fluid pressure within the tank, and a pump for drawing the natural gas fuel from the tank. An electronic controller is in communication with the pressure sensor and has a cryogenic system diagnostics algorithm executable thereon that is configured to receive a pressure signal from the pressure sensor, detect a cryogenic system fault based on the signal, and generate a notification signal based on the fault.

Abstract: A variable speed switch includes a switch main body portion which is accommodated in a housing of an electric power tool and mounted to the housing so as to be capable of relative movement, and a load sensor which is provided in the switch main body portion and capable of outputting an electric signal in proportion to the amount of distortion caused by a pressing force. The switch operating portion is mounted on the surface of the housing so as to be capable of relative displacement with respect to the housing and transmits a pressing force applied to the switch operating portion to the load sensor, with the maximum displacement amount of the switch operating portion being set to equal to or less than 5 mm.

Abstract: A process for validating the fault detection of a device under test includes carrying out a series of basic tests of the device under test. Each basic test leads to a positive or negative result indicating normal or abnormal functioning of the device under test. The process also includes, after each realization of a basic test, updating an event counter (CRT) and updating a result counter (FCRT). Validation is performed depending on test result once the event counter has reached a first maximal value (CTRmax) or once the realization counter has reached a second maximal value (FCTRmax). The process can be performed by a diagnostic device. The process and device can monitor the electric or functional performance of more or less complex systems installed in an automobile.

Abstract: A process for predicting longitudinal cracks during continuous casting of steel slabs. The local strand temperature is measured by thermocouples distributed in the mold wall. In this process, the risk of the strand rupturing as a result of longitudinal cracking is assessed statistically taking into account the current temperature values measured by the thermocouples arranged in the mold and the temperature values determined when no cracks are present.

Abstract: A method for identifying a piece of wood amongst a plurality or for determining its rotation includes the operating steps of: acquiring at least one piece of real X-ray information about the piece of wood; calculating, based on a tomographic reconstruction, a piece of virtual X-ray information in the same way as in the acquisition of the real X-ray information; comparing the real and virtual X-ray information to verify whether they match; and repeating the calculation and comparison steps up to obtaining the matching, and/or, for identification method only, selecting a different tomographic reconstruction and reiterating the calculation and comparison steps and, if necessary, the repetition and/or selection steps.

Abstract: A plurality of RFIDs is installed on aircraft or other structure. The RFIDs can query one another upon original installation and in response to predetermined event detection, and determine their relative locations within a mesh. The determined location data and other information are stored within the respect memories of the RFIDs. The stored data can be later accessed and used in analyzing damage or structural failure of the aircraft. Corrective measures are thus expedited because before-and-after structural comparisons can be readily made, with or without reference to original engineering data for the aircraft.

Abstract: A method performed by a processing device, the method comprising: obtaining first waveform data indicative of traversal of a first signal through a structure at a first time; applying a scale transform to the first waveform data and the second waveform data; computing, by the processing device and based on applying the scale transform, a scale-cross correlation function that promotes identification of scaling behavior between the first waveform data and the second waveform data; performing one or more of: computing, by the processing device and based on the scale-cross correlation function, a scale factor for the first waveform data and the second waveform data; and computing, by the processing device and based on the scale-cross correlation function, a scale invariant correlation coefficient between the first waveform data and the second waveform data.

Abstract: The present disclosure relates to a method for automatically assessing structural characteristics of a supporting pole sunk in the ground, including the operational steps of detecting data regarding a pole being assessed, striking at least one blow against said pole, detecting pole oscillations generated by said struck blow(s), analyzing detected oscillations in order to determine at least one significant parameter of the oscillation trend, and comparing said significant parameter(s) with pre-established threshold values in order to obtain a conformity or non-conformity index related to pole characteristics.

Abstract: A method for detecting and determining a position of faults using reflectometry in a wired electrical network including: injecting a test signal e(t) into a cable in the electrical network, a timing of successive injections being controlled by a synchronization module that generates an emission clock signal and a reception clock signal; retrieving a reflected signal on the cable; sampling the reflected signal at a frequency Fe=1/Te, where Te is a sampling period; counting a number of samples obtained for the reflected signal and comparing the number of samples obtained with a number n predefined as a function of a length of the cable or the electrical network to be diagnosed, where n is an integer; repeating the injecting, the sampling, and the counting steps N times, shifting the emission clock signal by a duration ?; reconstituting the reflected signal from n*N samples obtained; and analyzing the reconstituted reflected signal to detect a fault.

Abstract: A system and method for computerized grading of the cut of a gemstone. The system includes a gemstone model and an illumination model. The gemstone model defines the cut of the gemstone in three dimensions with reference to the facets of the gemstone. The illumination model defines light projected onto the gemstone. The method includes the steps of determining a beam of light refracted into the gemstone from the illumination model for at least one of the facets, tracing reflections of the beam of light within the gemstone, and measuring at least one light beam refracted out of the gemstone model. The measurements of the refracted light are used to evaluate the gemstone.