Search

The article aims to assess the roughness of parting surfaces in the context of abrasive water jet technology for various materials. The evaluation is based on the feed speed of the cutting head, which is adjusted to achieve the desired final roughness, taking into consideration the stiffness of the material being cut. We used non-contact and contact methods to measure selected parameters of the roughness of the dividing surfaces. The study included two materials—namely, structural steel material S235JRG1 and aluminum alloy AW 5754. In addition to the above, the study involved using a cutting head with varying feed rates to achieve different surface roughness levels required by customers. The roughness parameters Ra and Rz of the cut surfaces were measured using a laser profilometer (laser profilometer). To ensure the accuracy of the laser profilometer, a control roughness measurement was conducted using a contact roughness gauge. The roughness values obtained for Ra and Rz from both measurement methods were plotted on a graph to illustrate their dependencies and were subsequently evaluated and compared. By measuring the roughness parameters Ra and Rz, the study was able to provide insights into the effectiveness of the cutting head’s feed rates in achieving the desired roughness levels. Additionally, by comparing the results of the laser profilometer and contact roughness gauge, the accuracy of the measurement non-contact method used in the study was verified.

Construction materials and related management, handling, and storage provisions account for a large portion of road construction expenses. For that reason, improved material flow monitoring techniques can achieve significant cost and time savings, as well as better quality control. This study assessed the performance of a solid-state pulsed time-of-flight laser lidar profilometer in measuring the volume of soil stockpiles and road layer thicknesses. The 3D (X, Y, Z, and intensity) image calculation was based on the analysis of multiple combined point clouds measured with an excavator-integrated profilometer. Error analysis confirmed the accuracy of road layer thickness estimation within one centimeter and an error level of approximately 3% when measuring soil stockpile volumes. In conjunction with a theoretical model of the superstructure, this 3D measurement technique can help contractors and supervisors ensure road quality.

Piles are slender members made of concrete, steel, aluminium or timber installed in the ground to transfer the loads to soils at some significant depth below the base of the structure. The material property of the pile influences load-deformation response, bearing capacity, surface roughness and interfacial shear behaviour. The current study aims at assessing interfacial friction through a series of laboratory studies using three different pile materials, viz. concrete, wood and aluminium with sand as infill material. The surface roughness of three pile materials is analysed using a three-dimensional optical profilometer. Among the three pile materials considered for the study, the abrasive action of infill on concrete is more evident due to granular particles’ intrusion on the cracked concrete surface. Wood and aluminium specimens developed enhanced tangential and adhesive action after shearing action. The three-dimensional profilometer studies could capture the abrasive action and subsequent wear and tear of the pile material.

The research aimed to integrate a solid-state 2D-pulsed time-of-flight (TOF) flash Lidar profilometer and a mechanically scanning 3D Lidar in order to monitor the 4D (3D + signal intensity) environment at a construction site from an excavator. Utilizing the excavator’s GNSS and IMU sensor data enables to fuse the profilometer and 3D Lidar point clouds into the same coordinate system. Both measurement devices have quite a narrow field of view, but the overall viewing angle is expanded due to the movement of the excavator boom and rotation of the excavator cab. The major advantage of this combination method is that the profilometer provides centimetre-accurate details of the worksite within a range of approximately 1–10 m, while the commercial 3D Lidar scanner provides a larger scale (roughly 1–64 m) description of the worksite with an accuracy of ±6 cm. Additionally, the profilometer’s intensity information can be used to identify people on the basis of varying reflective vest patterns. The experimental results indicate that our combination system can accurately build a quality 4D point cloud map better than either individual device on its own. The combination of Lidars could prove to be an interesting tool, with the potential to improve construction site management processes.

The main thesis of this paper was to briefly describe the measurement technique using a non-contact laser profilometer. This paper is divided into several parts, where in the introduction, in the theoretical analysis, we described the necessity of using control mechanisms in automation. Then, in the second chapter, we have developed the technology of measurement with a profilometer and its application in scientific work and in practice. In the experimental part, we have defined the application of a profilometer in laboratory conditions on an automated line in the measurement of a part printed with a 3D printer. Finally, we evaluated the advantages and disadvantages of this device compared to mechanical measuring devices.

In orthodontic diagnosis and treatment planning, soft tissue profile assessment is of prime importance. Due to the emerging soft tissue paradigm, greater emphasis has been given to the clinical examination of soft tissue function and esthetics. Various cephalometric and photographic methods were introduced in the past to assess and measure profile angle and other facial angles. Our new device, that is, profilometer, helps to measure profile angle clinically.

We considered Class II dental cavities in critical tooth areas concerned with vital pulp therapy, and evaluated the marginal gap after treatment with Biodentine and Geristore, and one composite after either etching and adhesive (V2) and after use of a self-etching system (iBond Universal). We measured the surface morphology at the marginal gap by optical profilometry, and carried out analysis of the 3D data according to a new effective definition of marginal gap. The defined quantity was assessed for statistical significance of the apparent differences. The largest gaps appeared for Geristore (first) and Biodentine (not significantly lower), whereas the gaps of the composite controls were both lower, the lowest being the two-step self-etched system with respect to the three-steps etched and adhesive system, yet without statistical significance. Obviously, there is still room for improvement of the vital pulp therapy restorative materials, as compared to the use of standard composite systems.

This paper investigates a cantilever beam nonlinear dynamic behaviour, on which the nonlinearity is introduced with permanent magnet interactions or with a non-holonomic contact. The experimental time domain responses obtained from non-zero initial conditions are measured using a laser profilometer, conventionally adopted for product shape detections in online industrial applications. The Fourier transform, Continuous Wavelet transform, and Hilbert transform are used to investigate nonlinear phenomena in the frequency content, highlighting advantages and drawbacks of the three methods in catching instantaneous phenomena. Then, a Multi-Phi approach is proposed to describe the time evolution of nonlinear systems by means of a discrete number of linearised systems. Therefore, two linearised models have been developed and tuned to describe the dynamic behaviour of different Euler–Bernoulli cantilever beam configurations. The experimental data of nonlinear systems are compared with the corresponding ones of the linear system to evaluate the effects of introduced nonlinearities on the overall dynamic properties.

The research problem of a surface’s profile with an extended precision detail of irregular shape with a given accuracy is considered by the contactless scanning profilometer. The contact of the measuring block with a controlled surface needs to be excluded because of a possibility of damage of a product and, at the same time, to provide the necessary accuracy of assessment of its profile. For the solution of this task in work the double-circuit system containing two sensors is used: the distance converter on the basis of optical tunneling for the “exact” channel and the converter on the basis of a chromatic aberration for “rough” channel of scanning. It is shown that based on these measurements of the “rough” channel providing the guaranteed exception of contact of “rough” channel’s contact with a surface of the studied product. It is possible to predict situation and traverse speed of the sensor of the “exact” channel for the purpose of an exception of contact with the studied surface and ensuring necessary accuracy of measurements. The mathematical model of a dynamic system of scanning based on a prior information about entering it elements and blocks is developed. The analysis of the main dynamic properties of a system of scanning is carried out and the law of its management providing the required quality of transition processes based on mathematical modeling is constructed. The algorithm of the forecast of the subsequent position of the sensor of the “exact” channel based on these measurements of “rough” channel, which provides the required speed and accuracy of scanning depending on the predicted object’s surface profile height is developed. The flowchart of the algorithm determining the value of movement of the sensor of the “exact” channel in the vertical direction depending on the received assessment of measurements of “rough” channel is developed. The conducted researches allowed developing the block diagram of a double-circuit measuring system. Modeling of this system in the environment of MATLAB/SIMULINK, which allowed evaluating efficiency of its functioning for the different studied profiles was carried out. Results of modeling showed efficiency of the offered scheme of a profilometer’s control system.

The purpose of the present study is to perform an objective evaluation of the roughness measurements from connected vehicles equipped with software from Nira Dynamics AB (Nira). The focus of the study is to determine the quality of the estimated IRI from the connected vehicles, regarding both daily and aggregated long-term data. The quality will be determined by comparing with a dedicated road surface measurement vehicle (VTIRST) from the Swedish National Road and Transport Research Institute (VTI) which is approved according to the Swedish Transport Administration's “Technical approval for road surface measurement”. The study shows that the Nira estimated IRI is not quite the same as the IRI from the VTIRST. Nira’s estimated IRI may, however, be seen as a different index of road roughness, that may well be used in parallel with the standardized IRI. Also, the algorithms used by Nira can most likely be improved and produce a result closer to IRI from the VTIRST. Syftet med föreliggande studie är att göra en objektiv utvärdering av jämnhetsmätningar från uppkopplade fordon utrustade med programvara från Nira Dynamics AB (Nira). Fokus är att bestämma kvaliteten på uppskattad IRI (International Roughness Index) från de uppkopplade fordonen, avseende både dagliga data och aggregerade långtidsdata. Kvaliteten bestäms genom att jämföra data från de uppkopplade fordonen med ett dedikerat fordon för vägytemätning (VTIRST) från Statens väg- och transportforskningsinstitut (VTI) som är godkänt enligt Trafikverkets ”Tekniskt godkännande för vägytemätning”. Studien visar att Niras uppskattade IRI inte är riktigt detsamma som IRI från VTIRST. Niras uppskattade IRI kan dock ses som ett annat index för vägojämnheter, som mycket väl kan användas parallellt med den standardiserade IRI. Dessutom kan algoritmerna som används av Nira med största sannolikhet förbättras och ge ett resultat som ligger närmare IRI från VTIRST.

In profilometry systems, the conventional optical configuration of fringe projection with the oblique projection and camera axis perpendicular to the field of view requires complicated calculus and exact ray trace designs to get the 3D shape under question accurately. Moreover, when the optical components of the camera and projector and their internal placement are unknown, as is the case with commercial digital video projectors, the correct alignment of these components is uncertain, needing complex methods of calibration to correct the measured shape. In this work, we re-introduce a parallel-optical-axes configuration for a DIY profilometer that simplifies the calibration by a simple trigonometric relationship obtaining the topography with a resolution and accuracy similar to conventional arrangements that require non-simple relationships among phase and height. Furthermore, an experimental method is presented to locate the divergence point within the projector, which allows optimizing the projection and observation distances. The proposed calibration procedure allows proper compensation for the apparent scale change caused by perspective. The performance of the proposed method is tested in an optimized configuration and a non-optimized one, comparing the measurements with a Coordinate-measuring machine. The optimized optical system using simple spatial phase unwrapping shows an improved RMS error of 53 µ m versus 203 µ m of the non-optimized.

The swing arm profilometer (SAP) has been widely used to test large aspheric optics by measuring the asphericity from its best-fitting sphere (BFS). To further improve the test accuracy, we propose a pose-varied test mode for the SAP with a shorter-range probe to measure off-axis aspheric surfaces with stronger asphericity. In contrast to the classical SAP mode in which the air-table is fixed in a stationary position during measurement, we adjust the pose of each scan arc to match the local BFS and the measurement range of the probe decreases to half that of the global asphericity. To verify the effectiveness, we conduct experiments on an off-axis asphere with a diameter of 3 and 2 m. Compared with a classical SAP mode, it achieved an improved performance of 50% higher repeatability and 32% higher accuracy.

The aim of this study is to evaluate the effect of whitening toothpaste on the surface roughness of resin-based restorative materials by different measurement methods. Twenty four specimens from each of human enamel, a microhybrid composite and two nanohybrid composites discs (8.0 diameter × 4.0 mm thick) were divided into two groups (n = 12) according to toothbrushing solution and subjected to simulation toothbrushing (30,000 cycles) with both distilled water and whitening toothpaste containing blue covarine. Surface roughness was examined using atomic force microscopy (AFM), profilometer, and scanning electron microscopy (SEM), and the data obtained were subjected to analysis. Ra values of Tescera (TES) were significantly higher than Sonicfill 2 (SF2) when brushing both toothbrushing solutions for initial or 30,000 cycles. Roughness increased for SF2 and TES when brushed for 30,000 cycles and was higher than enamel and Herculite XRV Ultra (HXU). Human enamel was obtained lower surface roughness values brushed with toothpaste compared with distilled water. Evaluation of the surface roughness of control groups using the AFM revealed no statistically significant difference between the groups, but significant differences were found using a profilometer. The use of abrasive whitening toothpaste containing blue covarine and the number of brushing cycles affect the surface properties of human enamel and the restorative material, and also, the clinical success of the restoration. Toothbrushing for 30,000 cycles increased the surface roughness of all materials. The type of toothbrushing solution partially has affected surface roughness.

SIGNIFICANCE Anterior eye shape measurements are important for clinical contact lens fitting. The detailed assessment of measurement repeatability using the Eye Surface Profiler (ESP; Eaglet Eye B.V., AP Houten, the Netherlands) allows for more reliable interpretation of eye surface topography measurements. PURPOSE This study aimed to determine the repeatability of the ESP for anterior central corneal power and anterior eye surface height measurements. METHODS A Badal optometer was mounted on the ESP to provide an external fixation target with appropriate accommodation control and refractive correction. Forty-five healthy young adults underwent two sessions of anterior eye measurements, separated by 20 minutes, using the ESP. In each session, three consecutive scans were captured. Sagittal height data were obtained from 8-mm central cornea and from 8- to 14-mm diameter (encompassing the corneal periphery and anterior sclera). Anterior corneal powers were determined from the central cornea. Intersessional and intrasessional repeatability values were determined as coefficients of repeatability and root mean square error differences. RESULTS Sagittal height intersessional coefficients of repeatability for central nasal (5 μm) and central temporal (7 μm) were better than peripheral nasal (24 μm) and peripheral temporal (21 μm) regions. Sagittal height intrasessional coefficients of repeatability were 9, 8, 28, and 31 μm for central nasal, central temporal, peripheral nasal, and peripheral temporal regions, respectively. Intersessional coefficients of repeatability of mean sphere, 90/180° (J0) astigmatism, and oblique (J45) astigmatism were 0.67, 0.22, and 0.13 D, respectively, with corresponding intrasessional coefficients of repeatability of 1.27, 0.21, and 0.27 D. CONCLUSIONS The modified measuring procedure for the ESP used in this study provides highly repeatable sagittal height measurements in the central cornea but is less repeatable in the corneal periphery and scleral region. Results of the current study can be considered when using ESP in the interpretation of anterior eye surface shape measurements and in contact lens fitting and design.

Contraposing the surface quality testing of a Wolter-I type mandrel after ultraprecise turning, we propose a measuring method based on a contact-type profilometer and fabricate an adjusting device to assist in measurements. By coordinating probe translational motion in the Z and Y directions, this device provides 6 degrees of freedom. Extracting the feature point on the curve of a meridian section contour, the measurement data of the two aspherical surfaces that constitute a Wolter-I type mandrel can be segregated. This feature point is used as a reference point to make the measurement coordinate and machine coordinate systems coincide with each other in order to calculate the dimensional errors of the mandrel. By choosing samples of different lengths, some property indexes of the mandrel surface, such as roughness, waviness, and form error, can be extracted from the contour error signals via the wavelet transform method. This proposed method can solve the problem that the aspheric surface dimension error and contour form error of the Wolter-I mandrel surface cannot be measured by the profilometer when the aspheric reference vertex cannot be determined. Using this method, only one measuring instrument is required to evaluate the mandrel after diamond turning, which can improve the measurement efficiency, and cover the full spatial wavelength range from the figure error to the surface roughness. In addition, this method has the potential to achieve the in situ measurement of the surface of the Wolter-I type ultra-precision mandrel.

BACKGROUND: The use of 3D printed material in the dental field is gaining tremendous attention. However, studies related to 3D printed denture resins are scarce and need consideration before their inclusion in routine clinical practice. OBJECTIVE: This study aimed to assess the surface roughness (Ra) of 3D printed denture resins following aging and mechanical brushing. METHODS: Forty round samples (diameter, 10 mm and thickness, 3 mm) were fabricated from two 3D printed (DentaBASE and Denture 3D+) and one conventional polymethylmethacrylate (PMMA) denture materials. The samples were thermo-cycled, subjected to mechanical brushing, and later immersed in either artificial saliva (AS), coffee, cola, or lemon juice (n= 10) to simulate one and two years of oral use. Surface roughness (Ra) was determined using a non-contact profilometer and scanning electron microscope was used for qualitative analysis. The data was analyzed using SPSS v.20 (α= 0.05). RESULTS: Denture 3D+ demonstrated highest mean Ra (1.15 ± 0.28 μm), followed by PMMA (0.99 ± 0.50 μm) and DentaBASE (0.81 ± 24). The difference in mean Ra between the materials was statistically non-significant (P= 0.08). Amongst the different beverages used, the highest Ra was observed for samples immersed in lemon juice (1.06 ± 0.40 μm) followed by cola (1.04 ± 0.46 μm) and coffee (0.98 ± 0.40 μm), respectively. The lowest Ra was observed for samples immersed in AS (0.85 ± 0.24 μm). CONCLUSION: The surface roughness of 3D printed denture resins was comparable with that of conventional PMMA resins. Denture 3D+ demonstrated the highest mean roughness, followed by PMMA and DentaBASE.

This Thesis for the degree Grado en Ingeniería de Tecnologías y Servicios de Telecomunicación (GITST) has been developed at Centro de Materiales y Dispositivos Avanzados para las TIC (CEMDATIC), at Departamento de Tecnología Fotónica y Bioingeniería (TFB), at Escuela Técnica Superior de Ingenieros de Telecomunicación (ETSIT), at Universidad Politécnica de Madrid (UPM). Microelectronics and nanotechnology research laboratories use surface characterization systems known as profilometers. These can be of two types, optical and mechanical. Usually, over the years, the software becomes obsolete, making it impossible to install it on current computers, or the electronic circuits break down. However, these equipments are still excellent in terms of their mechanical construction. At CEMDATIC, there is a DEKTAK IIA unit with broken electronics that is intended to be renewed. This instrument is a mechanical profilometer that allows acquiring the morphology of a sample by sweeping a tip over its surface. The purpose of this project is to design an electronic system to replace the original DEKTAK IIA electronics, providing it with a new control software. The electronics are controlled by an Arduino Uno microcontroller programmed in C++. This device is responsible for controlling the motors, the detector head and transferring the data to/from the computer. A user interface has been programmed that allows control of the instrument and visualization of the data. The developed system has been validated by carrying out some preliminary measurements, detecting height variations of less than 30 µm

The aim of this study was to evaluate the roughness of the apical surface after apical resection performed by six different methods with an optical profilometer. Sixty human single root premolar teeth were used in this in vitro study. After root canal preparation, root canals were filled with gutta-percha and AH Plus root canal sealers by lateral condensation technique. The teeth were randomly divided into six groups according to the apical resection method: steel fissure bur, tungsten carbide fissure bur, Lindeman bur, diamond fissure bur, laser, and ultrasonic surgical piezo with a diamond tip. The root ends were resected 3 mm away from the root apex and at a 90 degrees angle. The time required for apicectomy was recorded for each group. After apical resection, the root surfaces were analyzed by an optical profilometer. The Kruskal-Wallis method was used to analyze the differences between groups. The significance level was set at 5%. The roughest surfaces were obtained by laser (25.54 +/- 9.01 mu m) and Lindeman bur (17.35 +/- 6.03 mu m), respectively. The longest mean resection times were recorded in piezosurgery and laser surgery (57 +/- 14.39 s and 50.9 +/- 16.86 s), respectively. Although the diamond-tipped piezo surgical cutting time is long, it has the best results in terms of surface roughness (5.50 +/- 1.73 mu m). The optical profilometer is a more convenient tool for evaluating the surface after apical surgery, as it provides an opportunity to evaluate objectively with both visual and numerical data.

The goal of this study is to look at the development and use of green inhibitors in the electropolishing process (EP), as well as their potential as an anti-corrosive coating for C-steel in an acidic medium. We can replace environmentally dangerous substances with inexpensive, effective molecules that have little or no negative environmental impact like amino acids which are employed as safe inhibitors. The EP characteristics of C-steel were measured by galvanostatic techniques with different concentrations of amino acids over a wide range of (1-1000 × 10−6 mol/l) and temperatures (298–313 K). The findings indicate that the electropolishing behavior of C-steel is governed by mass transfer, with Fe2+ being proposed as the governing species for the salt film mechanism during anodic dissolution in the limiting current plateau. The experimental results indicate that increases in the amino acid concentrations inhibit the EP by 83.33% in the case of L-Methionine at 298 K. Density Functional Theory (DFT) was used to optimize geometry in the gas and liquid phases. The inhibition efficiency was associated with global reactivity descriptors, Fukui indices and dual local descriptors. The inhibitory performance is in good agreement with the estimated quantum chemical parameters, according to our findings.

An astigmatic optical profilometer is a precision instrument with advantages such as high resolution, high bandwidth, a compact size, and low cost. However, current astigmatic optical profilometers measure only surface morphology, and their potential for capturing subsurface information remains underutilized. In this study, we developed a method for measuring the thickness of transparent thin films with an astigmatic optical profilometer. Experimental results demonstrate that the thickness of transparent films tens of micrometers thick can be accurately measured. The maximum thickness measurable through our system is approximately 100 μm, which may be increased to 1.2 mm through the use of a scanner with a greater travel range. A coupling problem occurs for films

The modification of a domestic series profilometer (model 130) is carried out. The device is additionally equipped with an easily mountable rod, on which a support ball is installed, displaced relative to the measuring needle by 30 mm. By moving the ball along the reference plane, it is possible to measure correctly both the micro- and the macroprofile (shape) of a surface along the needle path with a maximum length of 12.5 mm. Measurement results obtained using the initial and modified schemes are compared. It is shown that they coincide with a precision of 0.1 µm. Systematic errors and the accuracy of measurements for the initial and modified schemes of the device are determined. The results of measurements of the transverse profile of the etching grooves over a length of 12 mm are presented. The shape of the surface of a cylindrical X-ray mirror is measured over a length of 40 mm.

Methods for increasing the measurement range of the height of surface profile by the interference profilometer are proposed. The methods are based on using of multiple light sources with different wavelengths. It was shown experimentally that the measurement range increased at least 5 times due to using of two wavelengths, and at least 7 times due to using three wavelengths, while maintaining the resolution of the measurements.

In controlling the angle error of laser profilometer contact measurement, the control model used in the past is subject to more external interference, which affects the measurement of other parameters, resulting in poor error control effect. Therefore, the angle error control model of laser profilometer contact measurement is designed by determining the initial zero position of the profilometer measuring sensor, compensating the non-linear error, designing the interference signal processing circuit, and avoiding the error measurement influenced by external factors. From the main error sources such as the perpendicularity, standard error, sensor error and other errors of the coordinate axis of the profilometer, the accuracy is distributed. According to the equal action principle, the measurement uncertainty of the profilometer is calculated, and the measurement is obtained. According to the interference signal processing circuit and measurement index, the serial communication control circuit is designed, and the angle error control model of laser profilometer contact measurement is constructed. The experimental results show that the designed laser profilometer contact measurement angle error control model has high precision and does not affect other parameters in the control process, which shows that the control model has good effect in practical application.

Abstract Real-time, three-dimensional (3D) visualisation technology can be used at construction sites to improve the quality of work. A 3D view of the landscape under work can be compared to a target 3D model of the landscape to conveniently show needed excavation tasks to a human excavator operator or to show the progress of an autonomous excavator. The purpose of this study was to demonstrate surface visualisation from measurements taken with a pulsed time-of-flight (TOF) 2D profilometer on-board a semiautonomous excavator. The semiautomatic excavator was implemented by recording the feedback script parameters from the work performed on the excavator by a human driver. 3D visualisation maps based on the triangle mesh technique were generated from the 3D point cloud using measurements of the trenches dug by a human and an autonomous excavator. The accuracy of the 3D maps was evaluated by comparing them to a high-resolution commercial 3D scanner. An analysis of the results shows that the 2D profilometer attached to the excavator can achieve almost the same 3D results as a high-quality on-site static commercial 3D scanner, whilst more easily providing an unobstructed view of the trench during operation (a 3D scanner placed next to a deep trench might not have a full view of the trench). The main technical advantages of our 2D profilometer are its compact size, measurement speed, lack of moving parts, robustness, low-cost technology that enables visualisations from a unique viewpoint on the boom of the excavator, and readiness for real-time control of the excavator’s system. This research is expected to encourage the efficiency of the digging process in the future, as well as to provide a remarkable view of trench work using an excavator as a moving platform to facilitate data visualisation. Graphical abstract

A method for simultaneous laser profilometer and hand–eye calibration in relation to an industrial robot as well as its implementation is presented. In contrast to other methods, the new calibration procedure requires the measurement of only one reference geometry to calculate all the transformation parameters. The reference geometry is measured with a laser profilometer from 15 different poses. The intrinsic parameters of the profilometer, as well as the extrinsic (hand–eye) parameters, are then numerically optimized to achieve the minimum deviation between the reference and the measured geometry. The method was characterized with experiments that revealed a standard deviation of the displacements between the reference geometry after the calibration of less than 0.105 mm in the case of using the robot-arm actuator and 0.046 mm in case of using a 5-axis CNC milling machine. The entire procedure, including measurement and calculation, can be completely automated and lasts less than 10 min. This opens up possibilities for regular on-site recalibration of the entire system.

Surface profilometry techniques such as coherent scanning interferometry or focus variation require long scan times and are thus vulnerable to environmental disturbance. Hyperspectral interferometry (HSI) overcomes the problem by recording all the spatial and spectral information necessary to reconstruct a 2D surface height map in a single shot. In this paper, we present a new HSI system that uses a pinhole array to provide the necessary gaps for the spectral information. It is capable of measuring 2500 independent points, twice the previous maximum number, with a maximum unambiguous depth range of ∼825 µm and a larger maximum surface tilt angle of 33.3 mrad. The use of phase information allows height to be measured to a precision of ∼6 nm, an order of magnitude improvement on previous HSI systems.

We examined hematological changes influenced by the experimental hypervitaminosis A. The 3D confocal optical profilometer was applied for assessment of the erythrocytes’ membrane structural changes influenced by an overdose of vitamin A. The blood smears were evaluated in terms of alterations of geometrical and optical parameters of erythrocytes for two groups of animals: oil base and retinol palmitate (n = 9 animals for each group). The results demonstrate that an overdose of retinol palmitate causes changes in the torus curvature and pallor of discocytes, their surface area and volume. The observed structural malformations of the shape of red blood cells become visible at the earlier preclinical stage of changes in animal state and behavior. With this in mind, the results of the study open a new area of research in the certain dysfunction diagnosis of red blood cells and have a great potential in the further development of new curative protocols.

A new optical configuration of digital holography that employed two multi-reflection reference mirrors is proposed. The number of reflectance orders from the reference mirrors was doubled from the previous research of the digital holography it allows recording more interference fringes without the expansion of the camera’s sensor size. The proposed double multi-reflection reference mirrors can improve the measurement range to twice better than single multireflection reference mirrors e without any degradation of without any degradation of the spatial resolution. The new system can also help to avoid the low fringe contrast of the interference pattern of the high reflection order.

The focus of this study is to discuss the metrological performance of a first prototype of a vision-based measurement system targeted to in-production dimensional quality control of turned parts. The instrument exploits telecentric optical profilometry, is characterized by short inspection time and is suitable for automated charge/discharge of the parts to be inspected. Section II discusses those mechanical arrangements targeted to optimize images acquired as well as the main issues that eventual mechanical misalignments of components might introduce in the quality of images. Section III describes a comparison analysis performed on measurements collected both with the aforementioned instrument and other on-the-market devices commonly used in production line. The data acquired are presented in section IV and were useful to evaluate the metrological performance of each instrument and the combination of the variability of the instruments and the variability of the parts.

Background: This study aimed to assess the marginal adaptation and internal fit of cobalt-chromium copings fabricated by the selective laser melting (SLM) and conventional techniques using a profilometer. Materials and Methods: In this in vitro study sample size was calculated to be a total of 10 in two groups (n = 5). A brass model was used that had a circular cross-section with a round shoulder margin with 0.5 mm thickness and axial walls with 10 mm length and 6° taper. The copings fabricated with both techniques (SLM and casting method) were placed on the model, and vertical marginal gap was measured using a profilometer. The internal fit of copings was assessed by weighing the light-body addition silicone applied inside them, which simulated the cement. Data were analyzed through parametric (Independent t-test) and nonparametric (Mann–Whitney U-test, Bootstrap, Spearman, and Pearson Correlation) analysis. All analyses were performed at a significant level (α = 0.05) using SPSS. Results: The mean marginal gap in the casting group (132.93 ± ) was significantly higher than that in the SLM group (67.14 ± 15.67 μm) (P < 0.05). The mean weight of light-body silicone was 9.60 ± in the SLM and 8.70 ± 1.21 mg in the casting group. No significant difference was noted between the two groups regarding the internal fit (P > 0.05). Conclusion: The copings fabricated by the SLM technique showed a smaller vertical marginal gap compared to the casting group. However, the two groups were not significantly different in terms of internal fit.

Profilometers are instruments commonly used in surface metrology tasks. These instruments play a key role in the industry, such as in manufacturing and quality assurance. However, conventional profilometry techniques require direct contact with the object. In this work, we developed a practical and low-cost optical profilometer for contactless profilometry. The proposed profilometer is based on a laser triangulation system. A laser spot is projected onto the surface of an object, which is captured by a camera. The images are processed to detect the laser spot's location and obtain the object's surface height through calibration. We designed and built the translation stage to process the object's surface. Finally, encouraging results show that the profilometer provides high accuracy with fast acquisition. © 2020 IEEE.

At present, in the Joint Institute for Nuclear Research (JINR), Dubna, Russia, experiments to study the process of inelastic scattering of fast neutrons with the nuclei of various substances are being conducted in the frame of the TANGRA (TAgged Neutron and Gamma RAys) project. The existing TANGRA facility allows to obtain precise information about the angular and energy distributions of gamma-rays resulting from the inelastic scattering of 14.1 MeV neutrons on complex nuclei. As source of neutrons, we used a portable neutron generator ING-27 ( E n = 14 . 1 MeV ), designed and created by VNIIA (Moscow) with an embedded double-sided 64-pixel silicon (gallium arsenide) alpha-particle detector, by means of which 64 independent tagged neutron beams are formed. Tagging of neutrons is done by registration of the alpha particle, produced in the binary reaction d + t → ( α + n), which is emitted in direction almost opposite to that of the neutron. To obtain correct information about the characteristics of the process of inelastic neutron scattering on nuclei, it is necessary to know the parameters of all 64 tagged neutron beams with good accuracy. To solve this problem, we have developed and created a two-coordinate position-sensitive silicon detector of fast neutron (profilometer), by means of which we measured the characteristics of all the 64 tagged neutron beams. In this paper we give a description of the design of the profilometer and present the results from the measurements of profiles of 64 tagged neutron beams formed by ING-27.

This paper proposes a systematic procedure for the quantitative analysis of the surface changes caused by ablation of carbon-based ablators using a high-resolution non-contact profilometer. The ablation tests were performed under high enthalpy flow conditions using a 0.4 MW arc-heated wind tunnel. The high-resolution profilometer was used to measure the surface data of carbon-based ablators. The key parameters for the analysis of the surface changes, such as surface recession and roughness, were calculated by the proposed procedure. In addition, a finite element model of the sample after the ablation test was constructed from the measured surface data. The proposed procedure can be effectively used to perform various analyses of the ablated surface using the measured data and numerical analysis method. Keywords: Carbon-based ablator, Ablation test, Surface recession

In food packaging, low-density polyethylene (PE) coating is applied to paperboards to act as a functional barrier and to provide the smoothness required to enhance printability. These characteristics are related to the material’s surface roughness, the parameter monitored during the manufacturing process. Measurement of surface roughness using optical profilometry has gained importance in the paper industry. The optical instruments used to measure surface roughness are limited spatially by the relationship with the light wavelength at which they operate. A scanning electron microscope (SEM) is an alternative for overcoming the spatial resolution limitation, and the use of stereo-photogrammetry on SEM images can be seen as an alternative profilometry technique to measure surface roughness. In this investigation, the surface topography of industrially manufactured high-quality PE-coated paperboard was studied, comparing the SEM stereo-photogrammetry technique with a reference profilometry method, i. e., chromatic confocal microscopy (CCM). We found close agreement between the calculated surface roughness and the results of the techniques used and compared them according to the new ISO 25178 Geometric Product Specifications. We concluded that SEM stereo-photogrammetry provides comparable accurate alternative profilometry method for characterizing the surface roughness of PE-coated paperboard in the micrometer scale.

Optical measurement of large freeform samples is often limited by the resolution, size and slope limits of measurement devices. This trade-off can be solved using stitching—which, however, creates several difficulties often linked to accuracy of movement of the sample or objective. We present a stitching multisensor freeform topography instrument based on scanning white light interferometer, confocal sensor and accurate movements of the sample tracked using laser interferometers. The interferometers track the sample in 2D at an accuracy of a few nm over a 10 cm × 10 cm area. The instrument is thoroughly characterized and uncertainty is estimated to ensure traceable results. Based on the characterization results the instrument allows topography measurement of freeform sample with 54 nm standard uncertainty for datasets of a few hundred sub-images.

Purpose: To evaluate the intrasession repeatability of corneal, limbal and scleral measurements obtained by an experienced operator with a Fourier transform profilometer in healthy eyes. Methods: Prospective, single-center study including 35 eyes of 35 participants with ages ranging from 13 to 52 years. All patients underwent three consecutive corneoscleral topographic evaluations with the Eye Surface Profiler (ESP) system (Eaglet Eye b.v.). Intrasession repeatability was analyzed for different geometric and sagittal height variables using the following parameters: the within-subject standard deviation (Sw) of the three consecutive measurements, intrasubject precision (1.96 × Sw), coefficient of variation (CV) and the intraclass correlation coefficient (ICC). Results: Inner best fit sphere (BFS) showed good repeatability, with ICC of 0.844. Higher variability was observed for the repeated measurements of limbus and outer BFS, with ICCs of 0.636 and 0.739, respectively. For mean corneal and scleral radius, ICCs were 0.933 and 0.888, respectively. The repeatability of all sagittal height data was good for all chords evaluated (11–15 mm), with Sw values from 0.02 to 0.11 mm, and ICCs from 0.568 to 0.909. A significant positive correlation was found between the magnitude of temporal-nasal sagittal height difference for all measured chords and its Sw associated. Conclusion: The ESP system can provide consistent measurements of sagittal height data for different chord diameters as well as for mean corneal and scleral radius in healthy eyes. Best fit approaches for limbal and scleral areas were less repeatable, although within a clinically acceptable range. This article is funded by the Project UAIND18−06B of the University of Alicante within the program “Ayudas destinadas a la formación predoctoral en colaboración con empresas 2018″ supported by the Vicerrectorado de Investigación y Transferencia de Conocimiento. The author David P Piñero has been also supported by the Ministry of Economy, Industry and Competitiveness of Spain within the program Ramón y Cajal, RYC-2016-20471.

The effect of surface roughness on the thermohydraulics in minichannels has been studied numerically. Fluid flow (at low Reynolds number) through a typical three-dimensional (3D) channel subjected to constant heat flux (at the bottom) is analyzed incorporating surface roughness on the solid–fluid interfaces characterized by its true random and nonperiodic nature. Two different approaches are adopted to model the rough channel surfaces. Topographic measurements have been performed on a stainless steel minichannel using an optical surface profilometer (OSP) to generate digital replica of the rough surface. Alternatively, the Gaussian function defined by two statistical parameters, namely average roughness (Ra) and correlation length (Cl), are employed to imitate the random nature of rough interface. At the outset, conjugate heat transfer simulations have been performed on the rough channel models and the results are validated against the experimental data. Finally, the effect of surface roughness on both local and global nondimensional performance parameters is analyzed and compared with findings from simulations performed on a similar smooth channel. The outcomes reveal an enhanced friction factor for flow over a rough surface, attributable to the near wall shear rate fluctuations experienced by the flow. Unlike smooth channels, the local Nusselt number (Nuy) exhibits continuous fluctuations along the channel axial length. The fully developed (Nufd) and the average (Nu¯) counterparts of the Nusselt number show enhanced magnitudes when compared to the theoretical predictions of the same in a smooth surface channel. This amplification can be attributed to two simultaneously acting factors: augmentation in heat transfer area and chaotic mixing due to flow perturbation. The magnitude of enhancement in terms of fully developed Nusselt number (Nufd) is roughly 1.3 times of its corresponding value in a smooth channel and the factor remains invariant of the supplied heat.

The term optical profilometry is used in relation to group of methods used in a rapid, non-destructive, and non-contact assessment of surface topography. Those methods playing a signifi-cant role in the area of a modern advanced laboratory and industrial 3D measurements. With the development of profilometric methods, a large progress in the construction of optical profilometric instruments and measuring sensors used in them, including confocal sensors based on the chromatic light aberration phenomenon (CLA) has been observed since several years. In the paper shows that the Talysurf CLI 2000 multisensory optical profilometer equipped with a CLA sensor can be used in high-accuracy 3D measurements of the uncirculated and circulated coins. The assessment of such type objects characterized by a high variability of altitude can be extremely helpful in analyzing the actual metrological properties of measuring equipment used in their measurements.

The goal of the work, described in this paper, was to examine and analyse measurement capabilities of GUM Length and Angle Department in measurements of step height/depth standards with the values below 1 μm (nanostandards), with 2D, and 3D surface characteristics. Measurements were performed with microinterforometer and stylus profilometer. Keywords: nanometrology, depth/height standards, microinterferometry, contact profilometry.

Additive Manufacturing (AM) has become one of the most popular manufacturing techniques in various fields. Their layer-by-layer printing process allows easier fabrication of complex geometries. However, the quality and accuracy of fabricated artifacts in these techniques have low repeatability. In the era of Industry 4.0 by using emerging sensory and data processing capabilities such as Laser Surface Profilometer (LSP) and Deep Learning (DL), it is possible to improve the repeatability and quality of AM processes. This work presents an in-situ quality assessment and improvement using LSP for data acquisition and DL for data processing and decision making. The utilized LSP module generates a point cloud dataset containing information about the top surface geometry and quality. Once the point cloud data is pre-processed, an improved deep Hybrid Convolutional Auto-Encoder decoder (HCAE) model is used to perform the artifact's quality measurement and statistical representation. The HCAE model's statistical representation is comprised of 9*9 segments, each including four channels with the segment's probability to contain one of four labels, 1) Under-printed region, 2) Normally printed region, 3) Over-printed region, 4) Empty region. This data structure plays a significant role in determining the commands needed to optimize the fabrication process. The implemented HCAE model's accuracy and repeatability were measured by a multi-label multi-output metric developed in this study. The assessments made by HCAE are then used to perform an in-situ process adjustment by manipulating the future layer's fabrication through the G-code modification. By adjusting the machine's print speed and feedrate, the control algorithm exploits the subsequent layer deposition, segment by segment. The algorithm is then tested with two settings that can cause defective parts: severe under-extrusion and over-extrusion conditions. Both test artifacts' quality advanced significantly and converged to an acceptable state by four iterations.

Additive Manufacturing (AM) has become one of the most popular manufacturing techniques in various fields. Their layer-by-layer printing process allows easier fabrication of complex geometries. However, the quality and accuracy of fabricated artifacts in these techniques have low repeatability. In the era of Industry 4.0 by using emerging sensory and data processing capabilities such as Laser Surface Profilometer (LSP) and Deep Learning (DL), it is possible to improve the repeatability and quality of AM processes. This work presents an in-situ quality assessment and improvement using LSP for data acquisition and DL for data processing and decision making. The utilized LSP module generates a point cloud dataset containing information about the top surface geometry and quality. Once the point cloud data is pre-processed, an improved deep Hybrid Convolutional Auto-Encoder decoder (HCAE) model is used to perform the artifact's quality measurement and statistical representation. The HCAE model's statistical representation is comprised of 9*9 segments, each including four channels with the segment's probability to contain one of four labels, 1) Under-printed region, 2) Normally printed region, 3) Over-printed region, 4) Empty region. This data structure plays a significant role in determining the commands needed to optimize the fabrication process. The implemented HCAE model's accuracy and repeatability were measured by a multi-label multi-output metric developed in this study. The assessments made by HCAE are then used to perform an in-situ process adjustment by manipulating the future layer's fabrication through the G-code modification. By adjusting the machine's print speed and feedrate, the control algorithm exploits the subsequent layer deposition, segment by segment. The algorithm is then tested with two settings that can cause defective parts: severe under-extrusion and over-extrusion conditions. Both test artifacts' quality advanced significantly and converged to an acceptable state by four iterations.

Additive Manufacturing (AM) has become one of the most popular manufacturing techniques in various fields. Their layer-by-layer printing process allows an easier fabrication of complex geometries. However, the quality and accuracy of fabricated artifacts in these techniques have low repeatability. In the era of Industry 4.0 by using the emerging sensory and data processing capabilities such as Laser Surface Profilometer (LSP) and Deep Learning (DL), it is possible to improve the repeatability and quality of AM processes. This work presents an in-situ quality assessment and improvement using LSP for data acquisition and DL for data processing and decision making. The utilized LSP module generates a point cloud dataset containing information about the top surface geometry and quality. Once the point cloud data is preprocessed, an improved deep Hybrid Convolutional Auto-Encoder decoder (HCAE) model is used to perform the artifact's quality measurement and statistical representation. The HCAE model's statistical representation is comprised of 9*9 segments, each including four channels with the segment's probability to contain one of four labels, 1) Under-printed region, 2) Normally printed region, 3) Over-printed region, 4) Empty region. This data structure plays a significant role in determining the commands needed to optimize the fabrication process. The implemented HCAE model's accuracy and repeatability were measured by a multi-label multi-output metric developed in this study. The assessments made by HCAE are then used to perform an in-situ process adjustment by manipulating the future layer's fabrication through the G-code modification. By adjusting the machine's print speed and feedrate, the control algorithm exploits the next layer deposition, segment by segment. The algorithm is then tested with two manually defected settings, one part with severe under extrusion and one with over extrusion parameters. Both test artifacts' quality advanced significantly and converged to an acceptable state by four iterations.

A European EMPIR project, which aims to use large-scale, 5 mm × 200 µm × 50 µm (L×W×H), piezoresistive microprobes for contact resonance applications, a well-established measurement mode of atomic force microscopes (AFMs), is being funded. As the probes used in this project are much larger in size than typical AFM probes, however, some of the simplifications and assumptions made for AFM probes are not applicable. This study presents a guide on how to systematically create a model that replicates the dynamic behavior of microprobes. The model includes variables such as air damping, nonlinear sensitivities, and frequency dependencies. The finished model is then verified by analyzing a series of measurements.