Papers by Keyword: Thickness Measurement

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Authors: Jin Hong Bian, Ji Lin Wang, Sen Xu, Tian Zhou
Abstract: Sub-pixel positioning is a key technology in geometry measurement field. Reckoning on the low accuracy of ordinary polynomial interpolation for sub-pixel positioning method because of losing the position of edge points, an improved Sobel edge detection method is first proposed, and then is applied to the thickness measurement system of cable sheath material. The experiment shoes that the edge coordinateonthe detected by our proposed interpolation method is more colse to the real edge than the original method.
Authors: Yao Hua Que, Shu Jun Li, Yan Li Liu, Xue Feng Zhang, You Song Yang, Da Fu Cui, Xian Long Liu
Abstract: This paper introduces an online thickness monitoring technology of blast furnace stack. It describes the composition of monitoring technology, the basic principles and requirements of thickness measurement, and the features and functions of monitoring technology. Finally, the application of this monitoring technology in blast furnace stack thickness is analyzed and summed up.
Authors: Rong Guang Jia, Chong Hong Zhang, Xin Fu, Tong Da Ma
Abstract: CBED and EELS are most common methods to determine the thickness of the TEM specimen. In this work, specimen thickness of He-ion irradiated Al is measured respectively by CBED and EELS under 200kV. The helium concentration and the atomic displacement damage level are 2000appm and 0.2dpa, respectively. The CBED results show that the measurements of extinction distance match the calculations of effective extinction distance considering the deviation vector of the crystal. Moreover, it is proven by modeling analysis that He-ion irradiation does not affect the thickness measurements of extinction distance. Compared with CBED, the specimen thickness, measured by EELS, is larger, and may be attributed to the decrease of the zero-loss peak due to a part of elastic scattering electronsloss and the larger inelastic scattering mean free path selected. The EELS measurement error is less than 20%,consistent with the accuracy (about 20%) byK. Iakoubovskiiet al.
Authors: Ping He, Meng Wang, Chao Liu, Ying Li
Abstract: Steel rolling occupies a very important position in the iron and steel industry. The thickness of the steel plate is a crucial index of the quality, so the automatic detection system for high-precision thickness of the steel industry has a vital significance. The traditional thickness instruments have X-ray thickness gauge and ultrasonic thickness meter while the X-ray thickness gauge has radiation which is harmful to human body and ultrasonic thickness has a lower precision. For these shortcomings, a high precision thickness gauge by laser sensor was designed. Presented the differential measurement method based on laser displacement sensor. Then using TMS320F2812 as main control chip designed the hardware of the system. Finally, software programming was completed based on the hardware design. By experiment research, the results show that the laser thickness gauge has advantages of high precision and high reliability. It has a high practical value.
Authors: Ya Wei Zhao, Ru Gao, Chun Yan Liu, Jing Zhang
Abstract: This system brings forward the CCD measurement method based on oblique laser triangulation , which to resolve the minimal thickness measurement precision problem, in this system use linear array CCD, then used CCD as a photoelectric conversion device, the image on the CCD image point displacement variation to realize planar sheet thickness measurement, design and construction of the contactless thickness measurement system. Finally, the experimental analyze the measurement error of the system, prove the feasibility and validity of the system.
Authors: Yen Liang Yeh, Cheng Chi Wang, Ming Jyi Jang, Yen Pin Lin, Kuang Sheng Chen
Abstract: This paper presents a high-precision, non-destructive measurement system for determining the thickness and refractive indices of birefringent optical wave plates. Significantly, the proposed method enables the two refractive indices of the optical sample to be measured simultaneously. The performance of the proposed system is verified using a commercial quartz optical wave plate with known refractive indices of 1.5518 e n = and 1.5427 o n = , respectively, and a thickness of 452.1428 μm. The experimentally determined values of the refractive indices are found to be 1.55190 e n = and 1.54281 o n = , respectively, while the thickness is found to be 452.189 μm, corresponding to an experimental error of approximately 0.046 μm. The measurement resolution of the proposed system exceeds that of the interferometer hardware itself and provides a simple yet highly accurate means of measuring the principal optical parameters of birefringent glass wave plates.
Authors: Yurie Okugawa, Naoki Asakawa, Masato Okada
Abstract: While it is important that evaluation of thickness of a product made with press working to evaluate a mold, currently, there is not an appropriate system which can measure thickness of a free curved plate. The study deals with a development of an automatic measurement and evaluation system for thickness of free curved plates, called Orthros. The system measures thickness of a plate with laser displacement gauges and an industrial robot. While the system has been capable for measurement of a relatively simple shaped workpiece, it had collisions between laser-path and workpiece for that of a complicated shape, owing to a geometrical limit about measuring posture of the gauges. In this article, a new method to detect collision and to avoid collision by changing measuring posture on the basis of CAD data is proposed. In the method, not only the geometrical characteristic of the laser-path but also the measuring error characteristic of the gauges depending on the measuring posture are considered and continuous measuring path having change in posture to avoid collision is devised. From the experiment result, it is confirmed that the proposed method has an ability to measure a thickness of a workpiece with complicated shape.
Authors: Elke Roller
Abstract: VTLG is a new type of laser-based strip thickness gauges for cold rolling mills and offersthe solution for strip thickness measurement that the industry has long been searching for:Irrespective of the alloy, contact-free, highly precise and reliable. This article describes thedevelopments which had to be done so that now with the VTLG a solution is possible that has notbeen possible to date.
Authors: Jordan Biglione, Yves Bereaux, J.Y. Charmeau, Renaud G. Rinaldi, Jean Balcaen, Sambor Chhay
Abstract: Single stage injection blow moulding process, without preform storage and reheat, could be run on a standard injection moulding machine, with the aim of producing short series of specific hollow parts. In this process, the preform is being blow moulded after a short cooling time. Polypropylene (Random copolymer) is a suitable material for this type of process. The preform has to remain sufficiently melted to be blown. This single stage process introduces temperature gradients, molecular orientation, high stretch rates and high cooling rates. These constraints lead to a small processing window, and in practice, the process takes place between the melting temperature and the crystallization temperature. To investigates the mechanical behaviour in conditions as close to the process as possible, we ran a series of experiments: First, Dynamical Mechanical Analysis was performed starting from the solid state at room temperature and ending in the vicinity of the melting temperature. Conversely, oscillatory rheometry was also performed starting this time from the molten state at 200°C and decreasing the temperature down to the vicinity of the crystallization temperature. The influence of the shear rate and of the cooling kinetics on the enhancement of the mechanical properties when starting from the melt is discussed. This enhancement is attributed to the crystallization of the material. The question of the crystallization occurring at such high stretch rates and high cooling rates is open. A viscous Cross model has been proved to be relevant to the problem. Thermal dependence is assumed by an Arrhenius law. The process is simulated through a finite element code (POLYFLOW software) in the Ansys Workbench framework. Thickness measurements using image analysis are performed and comparison with the simulation results is satisfactory.
Authors: Zhi Yuan Xu, Xin Jun Wu, Chen Huang, Yi Hua Kang
Abstract: Pulsed eddy current (PEC) technique has been successfully used for measuring wall thinning of carbon steel equipments without removal of the insulation. In field applications, the probe performance decreases in presence of ferromagnetic claddings. This paper presents a method based on saturation magnetization to solve this problem. The main principle of this method is to weaken the magnetic shielding effect of the cladding by magnetizing it to saturation. A U-shaped magnetizer is designed to realize this method. Contrast experiments are performed on a Q235 steel plate covered by a galvanized steel cladding. The experiment results show that the thickness measurement range and lift-off range are increased by applying this method to the common PEC probe.
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