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This paper investigates the significant factors influencing the measurement uncertainty of 3D laser scanners, an essential tool in industrial contexts for swiftly and accurately analysing complex geometric objects. Through a designed experimental study, parameters such as object size, surface texture, scanner resolution, and ambient light intensity were systematically varied to assess their impact. The results demonstrate that nominal shaft diameter, ambient light intensity, surface finish of the shaft, scan resolution, and the interaction between surface finish and resolution significantly affect repeatability. An empirical model was developed to predict repeatability in shaft diameter measurements. Additionally, the exploration of developer coating revealed its pivotal role in minimising errors stemming from reflective surfaces, underscoring its importance in ensuring measurement reliability. The main contribution of the paper belongs to the knowledge and practice of 3D laser scanning by offering practical recommendations and guidelines. [ABSTRACT FROM AUTHOR]

Background: The management of patients with slipped capital femoral epiphysis (SCFE) requires imaging diagnostics of good quality and accurate measurement of the degree of slippage. In Sweden, three different radiological methods are commonly used: the calcar femorale method; the Billing method; and the Head-shaft angle described by Southwick. Purpose: To evaluate whether any of the three most common methods used in Sweden to measure the slip angle was more useful and reproducible than the others. Material and Methods: Two experienced orthopaedists measured the slip angle in preoperative hip radiographs. Intra- and inter-observer variability between the two experienced observers and the reported value by clinicians who treated the child with SCFE was evaluated. Results: The intraclass correlation coefficient (ICC) confidence interval (CI) between the two experienced observers and the reporting clinicians overlapped for the three methods. In 37% of the cases, the difference was more than 5° between the experienced observers' measurement and the reported value by clinicians. The two experienced orthopaedists' intra- and inter-observer variability was low. Conclusion: The observer's experience is more important than the method of choice when measuring the slip angle in SCFE. The research group recommends the calcar femorale method due to its feasibility on the versatile and commonly used frog leg lateral view. [ABSTRACT FROM AUTHOR]

Faced with measurement conditions such as high-temperature forging, strict prohibition of surface contamination, and toxic environments, using the projection point of an optical target projector (referred to as an "optical projector") as a photogrammetric target has become a necessary method of high-precision industrial photogrammetry. In connection with the current industrial demand, we have analyzed the principles of optical projectors and introduced their optical characteristics and advantages in the field of industrial photogrammetry. On this basis, a series of tests such as brightness, roundness, and so on were conducted to determine the basic properties of the optical projector. A set of performance test methods including inner coincidence accuracy and outer coincidence accuracy were proposed; the tests included industrial photogrammetry system measurement repeatability, surface measurement precision, and a comparison test with laser tracker. The test conditions used optical projection points as the photogrammetry targets. The test results showed that the coordinate measurement repeatability of the industrial photogrammetry system is 0.010 mm, and the surface measurement precision is 0.007 mm under the condition of a single optical projector station, with little difference between the results under the condition of pasting retro-reflective targets. In the process of the comparison test with laser tracker, the image quality of the black measurement object obtained is obviously inferior to other surfaces, so the analysis of the point projector is greatly affected by the color of the measured object and other conditions, which provides a reference for the measurement object and application range of the industrial photogrammetric system based on optical targets. The results demonstrate the applicability and reliability of using the optical projection point of an optical projector as target points for photogrammetry. [ABSTRACT FROM AUTHOR]

Background: Hole drilling is a measurement technique used to determine near surface residual stresses and has been codified in ASTM E837-20. In ASTM E837-20, the minimum allowable distance to a free edge is prescribed as 1.5 times the gauge circle diameter. Objective: This work examines the effect arising from the distance from a free edge on a hole drilling measurement and provides an approach to determine residual stress for measurements where the edge distance is closer than that currently permitted by ASTM E837-20. Methods: Numerical experiments were performed to understand how the compliance matrices change when the distance from a hole drilling measurement to a free edge varies. In addition, a series of hole drilling measurements were performed at various distances from a free edge using a shot peened aluminum plate with a nominally equibiaxial stress state to demonstrate the approach. Results: The numerical experiments determined that the use of corrected compliance matrices is appropriate when the edge distance is as small as 0.35 times the gauge circle diameter. Physical measurements supported the use of custom compliance matrices for a given free edge distance and specimen thicknesses. [ABSTRACT FROM AUTHOR]

Background: There are various experimental measurement techniques used to measure residual stress and this work describes one such method, the slotting method, and its application to measure near surface residual stresses. Objective: This work examines its application to macro-scale specimens. Methods: A series of numerical experiments were performed to understand the size required to assume that the specimen is infinitely large, namely the thickness, width, and height. To assess measurement repeatability, 12 slotting measurements were performed in a shot peened aluminum plate. Results: The numerical experiments determined the specimen should have a thickness greater than or equal to 21.6 mm (0.85 in), a total specimen width (normal to the slot length) greater than or equal to 44.5 mm (1.75 in), and total height (parallel to the slot) greater than or equal to 38.1 mm (1.5 in) for the specimen to be assumed to be infinite. Slotting measurement repeatability was found to have a maximum repeatability standard deviation of 30 MPa at the surface that decays rapidly to 5 MPa at a depth of 0.3 mm from the surface. Comparison x-ray diffraction measurements were performed. Conclusions: Infinite plate dimensions and slot length were determined as well as measurement repeatability. Slotting was shown to have significantly better repeatability than X-ray diffraction with layer removal for this application.

Faced with measurement conditions such as high-temperature forging, strict prohibition of surface contamination, and toxic environments, using the projection point of an optical target projector (referred to as an “optical projector”) as a photogrammetric target has become a necessary method of high-precision industrial photogrammetry. In connection with the current industrial demand, we have analyzed the principles of optical projectors and introduced their optical characteristics and advantages in the field of industrial photogrammetry. On this basis, a series of tests such as brightness, roundness, and so on were conducted to determine the basic properties of the optical projector. A set of performance test methods including inner coincidence accuracy and outer coincidence accuracy were proposed; the tests included industrial photogrammetry system measurement repeatability, surface measurement precision, and a comparison test with laser tracker. The test conditions used optical projection points as the photogrammetry targets. The test results showed that the coordinate measurement repeatability of the industrial photogrammetry system is 0.010 mm, and the surface measurement precision is 0.007 mm under the condition of a single optical projector station, with little difference between the results under the condition of pasting retro-reflective targets. In the process of the comparison test with laser tracker, the image quality of the black measurement object obtained is obviously inferior to other surfaces, so the analysis of the point projector is greatly affected by the color of the measured object and other conditions, which provides a reference for the measurement object and application range of the industrial photogrammetric system based on optical targets. The results demonstrate the applicability and reliability of using the optical projection point of an optical projector as target points for photogrammetry.

Laboratory measurement of saturated hydraulic conductivity, Ks, of sieved and packed soil is important for many scientific purposes. A given soil mass can be used once or several times. Little is known of the dependence of the Ks data on the reuse of the same soil mass. For three loamy soils, this investigation tested reuse effects of exactly the same soil mass on determination of Ks with the simplified falling head technique. For a given soil, the Ks values of 15 repacked soil samples were determined by using the same soil for a total of eight times. The means of Ks, initially equal to 45–159 mm/h, depending on the soil, decreased by nearly two or three times with the reuse of the same material, and they settled on values of 23–59 mm/h by the end of the experiment. Low, stable and little variable (coefficients of variation ≤15%) Ks values were obtained after the soil was used three to five times although there was some sign that stabilization of Ks could also require more reuses. The soil became finer with more reuses and the textural characteristics of the undispersed soil explained a large amount of the mean Ks results (coefficient of determination between means of Ks and the mean weight diameter = 0.65–0.76, depending on the soil). Taking into account that the best procedure for determination of Ks of sieved and packed soil samples yields the lowest variability of the individual Ks data, the conclusion was that a soil pre‐treatment including several wetting and drying cycles should be realized to obtain a soil mass usable repeatedly. The history of the used soil mass should be reported in the investigations dealing with sieved and repacked soil samples. [ABSTRACT FROM AUTHOR]

The article presents the results of research concerning the analysis of the possibility of the innovative application of the LineScan non-contact laser measuring probe controlled by the ACCURA II coordinate measuring machine in the field of measurements of a selected cutting tool. In the study, the angle of a round cutting insert was measured. The influence of the selected elements of a measurement strategy i.e., the scanning speed v, the resolution k, and the number of measurement paths w on the repeatability of measurements and the value of the insert’s angle was determined. In both cases, the number of paths had the greatest impact. The best repeatability was obtained for the smallest distance between points (k = 0.1 mm) and the largest number of paths (w =10). For those measurement strategies, which differed in the scanning speed (1 and 3 mm/s), the detailed GR&R analyses were carried out by using the ANOVA and EMP methods. For strategies with the scanning speeds of 1 and 3 mm/s, the variance of the measuring system was 0.9% and 0.5% of the total variance, respectively. However, these differences in repeatability were not statistically significant. It has been shown that the selected methodologies of measurements and measurement data processing ensure good measurement repeatability of the selected geometrical feature of a cutting tool.

The article presents the results of research concerning the analysis of the possibility of the innovative application of the LineScan non-contact laser measuring probe controlled by the ACCURA II coordinate measuring machine in the field of measurements of a selected cutting tool. In the study, the angle of a round cutting insert was measured. The influence of the selected elements of a measurement strategy i.e., the scanning speed v, the resolution k, and the number of measurement paths w on the repeatability of measurements and the value of the insert's angle was determined. In both cases, the number of paths had the greatest impact. The best repeatability was obtained for the smallest distance between points (k = 0.1 mm) and the largest number of paths (w =10). For those measurement strategies, which differed in the scanning speed (1 and 3 mm/s), the detailed GR&R analyses were carried out by using the ANOVA and EMP methods. For strategies with the scanning speeds of 1 and 3 mm/s, the variance of the measuring system was 0.9% and 0.5% of the total variance, respectively. However, these differences in repeatability were not statistically significant. It has been shown that the selected methodologies of measurements and measurement data processing ensure good measurement repeatability of the selected geometrical feature of a cutting tool. [ABSTRACT FROM AUTHOR]

The repeatability of rail wheel damage measurements is considered in this study. The authors investigated the measurement repeatability of vertical force dependence on wheel-rolling surface damage nature and suggested ways to reach higher repeatability. To investigate wheel-rolling surface damage impact on vertical force measurement repeatability, the results of measuring forces with different measurement systems were compared first. Another critical issue was estimating the deviation field for the measured force values. The box and whisker principles were used. Different types (shapes) of rail wheel damages and rolling stock operating conditions were examined by field tests. The article presents the dependence determined by the authors, and how the repeatability of the wheel damage measurement depends on the speed of the rolling stock. [ABSTRACT FROM AUTHOR]

This article examines the precision of the contour method using five residual stress measurement repeatability studies. The test specimens evaluated include the following: an aluminum T-section, a stainless steel plate with a dissimilar metal slot-filled weld, a stainless steel forging, a titanium plate with an electron beam slot-filled weld, and a nickel disk forging. These specimens were selected to encompass a range of typical materials and residual stress distributions. Each repeatability study included contour method measurements on five to ten similar specimens. Following completion of the residual stress measurements, an analysis was performed to determine the repeatability standard deviation of each population. In general, the results of the various repeatability studies are similar. The repeatability standard deviation tends to be relatively small throughout the part interior, and there are localized regions of higher repeatability standard deviations along the part perimeter. The repeatability standard deviations over much of the cross section range from 5 MPa for the aluminum T-section to 25 MPa for the nickel disk forging. There is a strong correlation between the elastic modulus of the material and the repeatability standard deviation. These results demonstrate the precision of the contour method over a broad range of specimen geometries, materials, and stress states.

Non-invasive positron emission tomography (PET) of vascular inflammation and atherosclerotic plaque by identifying increased uptake of 18F-fluordeoxyglucose (18F-FDG) is a powerful tool for monitoring disease activity, progression, and its response to therapy. 18F-FDG PET/computed tomography (PET/CT) of the aorta and carotid arteries has become widely used to assess changes in inflammation in clinical trials. However, the recent advent of hybrid PET/magnetic resonance (PET/MR) scanners has advantages for vascular imaging due to the reduction in radiation exposure and improved soft tissue contrast of MR compared to CT. Important for research and clinical use is an understanding of the scan-rescan repeatability of the PET measurement. While this has been studied for PET/CT, no data is currently available for vascular PET/MR imaging. In this study, we determined the scan-rescan measurement repeatability of 18F-FDG PET/MR in the aorta and carotid arteries was less than 5%, comparable to similar findings for 18F-FDG PET/CT. [ABSTRACT FROM AUTHOR]

Copyright of Computer Measurement & Control is the property of Magazine Agency of Computer Measurement & Control and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The repeatability of rail wheel damage measurements is considered in this study. The authors investigated the measurement repeatability of vertical force dependence on wheel-rolling surface damage nature and suggested ways to reach higher repeatability. To investigate wheel-rolling surface damage impact on vertical force measurement repeatability, the results of measuring forces with different measurement systems were compared first. Another critical issue was estimating the deviation field for the measured force values. The box and whisker principles were used. Different types (shapes) of rail wheel damages and rolling stock operating conditions were examined by field tests. The article presents the dependence determined by the authors, and how the repeatability of the wheel damage measurement depends on the speed of the rolling stock.

Copyright of Transportation Science & Technolgy is the property of Transportation Science & Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Phenotypic trait data play a central role in ecology and evolutionary research. The quality of trait data, and the findings of subsequent analyses, depend on the quality of measurement. However, most studies overlook measurement accuracy in their study designs. We investigated the repeatability of five frequently used linear measurements of avian traits: wing length, tarsus length, bill length, bill depth and bill width and the validity of proxies for three traits: bill surface area, structural body size and tarsus size, using species from the infra-order Meliphagides (honeyeaters, fairy wrens and their allies). Repeatability varied between traits and across species for a given trait: traits larger than 13 mm showed high repeatability compared with smaller traits. By incorporating microCT technology, we showed that the formula for the surface area of a cone, a widely used proxy of bill surface area, accurately describes bill surface area within species. Surface measurement of tarsus and wing lengths were valid proxies for underlying osteology. We recommend preliminary estimation of repeatability should be undertaken for individual traits prior to data collection, in order to design suitable protocols that improve data quality, while optimizing costs involved, particularly for traits < 13 mm. [ABSTRACT FROM AUTHOR]

Purpose First, to describe a new method of assessing cephalopelvic disproportion by measuring the retropubic tissue thickness (RTT), and second, to determine whether RTT was associated with an eventual delivery by cesarean section. Methods Three-dimensional transperineal ultrasound scans were performed on 129 laboring nulliparous women to obtain 3-dimensional volume datasets for assessing RTT. RTT was measured off-line by three operators (A, B, and C) as the shortest distance between the capsule of the pubic symphysis and the outer border of the fetal skull. The intraoperator repeatability of operator A and the interoperator reproducibility among A, B, and C were determined. The RTT in women who were delivered by cesarean section due to failure to progress was compared to that of women who had a vaginal delivery. Results The intraoperator repeatability for RTT was 1.2 mm. The overall RTT interoperator interclass correlation was 0.97 (0.95-0.98). The RTT in women who had a spontaneous, instrumental, or cesarean delivery was 1.16±0.32 cm, 1.12±0.25 cm, and 0.94±0.25 cm, respectively. Women who were delivered by cesarean section had a significantly smaller RTT than women who had a spontaneous delivery (P=0.008). There was no statistically significant difference in RTT between patients who had a normal vaginal delivery and patients who had an instrumental delivery (P=0.990), or between those who had an instrumental delivery and those who had a cesarean delivery after the Bonferroni correction (P=0.120). Conclusion RTT can be measured with satisfactory intraoperator repeatability and interoperator reproducibility. RTT was significantly smaller in women who eventually had a cesarean delivery than in those who had a vaginal delivery.

Copyright of Journal of Food Safety & Quality is the property of Journal of Food Safety & Quality Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

We propose a method for quantifying the in situ heterogeneity of solid materials at the picogram test portion scale, illustrating its use by investigating the oxygen isotope ratio (18O−/16O−) of four quartz samples. Using secondary ion mass spectrometry, we could estimate the intrinsic heterogeneity using a large number (~ 100) of closely spaced duplicated measurements. An analysis of variance was then applied to these large data sets to extract the measurement repeatability (typically 0.10–0.15‰, 1s) from the total variability, thereby revealing a variability ranging from 0.18‰ to 2.3‰, which can be attributed to the genuine isotope ratio heterogeneities. A small proportion of outlying values were either rejected manually after inspection, or were accommodated using robust statistics. We also evaluated two distinct approaches for estimating and correcting instrumental drift; the use of a sub‐area of the test material (if shown to have sufficiently low heterogeneity) is judged to be preferable to using a piece of unrelated silicate glass that we believe to be homogeneous. We also compared three approaches for estimating measurement repeatability, from which we show that the ‘duplicate method’ applied to the reference material is preferable to using other methods based either on the drift monitoring material or on assessing residuals of the drift monitoring material after drift correction. Finally, here we propose a strategy for predicting the number of measurements on individual fragments of a material that would be required to achieve a specified target uncertainty. [ABSTRACT FROM AUTHOR]

• The proposed interferometer possesses not only the superior performance of conventional interferometers but also the advantages of high measurement repeatability and high tolerance to environmental disturbances. • The proposed interferometer is capable of thin-film thickness measurements. • Experimental results validate the proposed interferometer. • Experimental results show a measurement repeatability of up to 3 nm. • Experimental results agree with the interferometer's high resistance to environmental perturbations. Conventional optical interferometers utilized for gauging thin-film thickness can offer non-contact, high-resolution, and full-field measurements but have to endure the noise caused by environmental perturbations. Possessing not only the superior performance of conventional interferometers but also the advantages of high measurement repeatability and high tolerance to environmental disturbances, a common-path tandem interferometer was proposed. In this paper, the interferometer's measurement theory and experimental setup are demonstrated, and the experimental results from the uses of the experimental setup are then presented and discussed. The experimental results validate the interferometer and show a measurement repeatability of up to 3 nm, curve fitting inaccuracy is one reason causing the measurement error; in addition, the results agree with the interferometer's high resistance to environmental perturbations. [ABSTRACT FROM AUTHOR]

The rheological characterization of glass-forming liquids is challenging due to their extreme temperature dependence and high stiffness at low temperatures. This study focuses on the special precautions that need to be taken to accommodate high sample stiffness and torsional instrument compliance in shear rheological experiments. The measurement errors due to the instrument compliance can be avoided by employing small-diameter parallel plate (SDPP) rheometry in combination of numerical instrument compliance corrections. Measurements of that type demonstrate that accurate and reliable rheological data can be obtained by SDPP rheometry despite unusually small diameter-to-gap ( d/ h) ratios. Specimen preparation for SDPP requires special attention, but then experiments show excellent repeatability. Advantages and some current applications of SDPP rheometry are briefly reviewed. SDPP rheometry is seen as a simple and versatile way to measure rheological properties of glass-forming liquids especially near their glass transition temperature. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Zhejiang University: Science A is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The presented article focuses on measurements of extremely small dimensions in nanometrology using tactile probes. It addresses a newly developed method of precise measurements in nanometrology by touch probes, where the measurements are carried out on the machine SIOS NMM-1. The aim of this work is to determine accuracy of measurements on this machine. The main contribution of this work is a creation of a methodology for the measurement of precision parts and determination of accuracy of measurement when using this device in nanometrology. The work also includes methodology for the calculation of measurement uncertainty, a keystone in determining the accuracy of measurement in nanometrology. The article provides results of representative sets of measurements of ruby ball diameters, including the evaluation of statistical parameters and determination of the combined measurement uncertainty. [ABSTRACT FROM AUTHOR]

• Impacts of microphone positions were analyzed, and two-side placement method is recommended. • Repeatability of the RTT noise tests considering tire landing positions and RTT noise variability was investigated. • Impacts of abrasion cycles on abrasion effects were analyzed and when to terminate was determined. • The overall noise level increases with abrasion cycles and a linear relation between them exists. • Spectral difference in 1/3 octave band after different abrasion cycles is in frequency above 1000 Hz. Tire-pavement noise and its durability have long been investigated by onsite observations. This research aims to explore a laboratory evaluation method of tire-pavement noise deterioration that combines the Rolling Tire down Tester (RTT) with the accelerated abrasion machine. Firstly, microphone placement was determined and repeatability of the laboratory RTT noise test method was evaluated, considering tire landing positions and RTT noise variability. Secondly, impacts of abrasion cycles on abrasion effects were analyzed based on the selected multi-variable accelerated abrasion machine (MAAM). Finally, noise deterioration characteristics were investigated combining RTT with MAAM. Placing microphones on two sides is recommended and the abrasion is terminated after 24,000 abrasion cycles. Overall noise level arises with increasing abrasion cycles, and linear correlation exists. The laboratory changes of noise level, 1/3 octave band spectrum, and noise growth rates are generally consistent with previous research, demonstrating feasibility of evaluating noise deterioration combining RTT with MAAM. [ABSTRACT FROM AUTHOR]