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Page 695 of 977 Results 6941 - 6950 of 9762

M. Ueki, Jianxin Sun, K. Ueda
SIMULTANEOUS SUB-MULTIPLE CALIBRATION FOR BOTH MASS AND VOLUME OF WEIGHTS USING A MASS COMPARATOR SYSTEM WITH AN AIR-TIGHT CHAMBER

The National Metrology Institute of Japan has established a simultaneous sub-multiple calibration method for both mass and volume of weights using a newly developed mass comparator system with an air-tight chamber. In order to verify validity of this method, the sub-multiple calibrations of the masses and volumes are simultaneously made for weights from 100 g to 10 g of a weight set, and the expanded uncertainties of these calibrated results have been estimated.

J.-H. Choi, H. H. Choi
PREPARATION PROCEDURE FOR LOADING FLUX QUANTUM WEIGHTS ON PICONEWTON FORCE REALIZATIION SYSTEM

We present a preparation procedure for loading flux quantum weights on piconewton force standard system, being developed at KRISS, including the micropositioning of a cantilever device with a superconducting micro-ring. To locate the device at zero-magnetic-field position inside a high-field-gradient superconducting magnet, the behaviour of the mechanical resonance frequency of the device in magnetic fields were studied in a dynamic mode and used to probe the local magnetic field value at the device position. A vertical offset of a few hundred micrometers caused a shift of ~ 0.7 Hz to the resonance frequency of 1144.4 Hz, and was nulled by either additional uniform magnetic field or a z-axis nanopositioner. Nulling was also confirmed by a non-singular temperature dependence of the resonance frequency.

Marcin Gnyba
RAMAN DIAGNOSTICS OF CVD DIAMOND GROWTH

Development of Raman spectroscopic system for diagnostics of growth of diamond and BDD (Boron- Doped-Diamond) thin films during μPA CVD (Microwave Plasma Assisted Chemical Vapour Deposition) process is described. Raman studies of such films were carried out as in-situ monitoring of film deposition as ex-situ measurements conducted for a sample outside the reaction vessel after manufacturing process. Modular system for the in-situ monitoring equipped with fibre-optic probes, was designed and tested. Moreover, Raman and optical microscopy were applied after the process for more detailed study of the deposited films. Solid state lasers having wavelength of 532 nm were applied as the excitation sources. The most significant parameters of the deposited films like their molecular composition, presence of defects and rate of the film growth were evaluated.

Man Yong Choi, Hee Sang Park, Jeong Hak Park, Yong Hak Huh
DEFECT DETECTION IN WIND TURBINE BLADE COMPOSITE BY USING INFRARED THERMOGRAPHY

This study was conducted to investigate the non-destructive infrared-thermography assessment of composite materials for wind power blades, by simulating defects likely to occur during the manufacture and operation of blades and designing artificial quantitative-sized defects.
Through the optical-infrared thermography, this study was able to detect void defects and even inclusion defects inside GFRP, a blade material.

Jae-Keun Yoo, Seung Kwan Kim, Seung-Nam Park
SPEED LIMITATION IN SPATIAL UNIFORMITY MEASUREMENTS OF SOLAR CELLS USING A BEAM PROJECTOR

We examined the potential sources that limit the measurement speed in our recently demonstrated apparatus to inspect spatial uniformity of solar cells using a beam projector. Using a repeated trigger measurement function of the source-meter and fast moving video images, we showed that the measurement speed was mainly limited by the video signal modulation. As a result, reliable measurements of short circuit current with about 30 ms per position could be achieved.

K. Wasapinyokul, R. Leecharoen, S. Chanyawadee, R. Chuenchom, P. Jamparuang, K. Chumpol, C. Charoenkij, A. Krachangmol
EFFECTS OF INTEGRATING SPHERE CONDITIONS ON THE SPATIAL RESPONSE DISTRIBUTION FUNCTION IN THE TOTAL LUMINOUS FLUX MEASUREMENT

The spatial response distribution function of an integrating sphere, for the total luminous flux measurement, was experimentally studied under various conditions. The most apparent effect was the change of signal at the sphere wall around the photo-detector, which typically had higher amplitude than that of the rest. The signal amplitude of such area decreased regarding one of the following conditions: decrease in the reflectance of baffle back surface, decrease in baffle diameter, and increase in the distance between baffle and the detector. The size of area with high amplitude was increased when the aperture diameter of the scanning light increased.

Dong-Hoon Lee, Kee Suk Hong, Yong-Shim Yoo, Seongchong Park, Chul-Woung Park, Seung-Kwan Kim, Seung-Nam Park
THE KRISS PLUS (PULSED LASER-BASED UNIFORM SOURCE) FACILITY FOR MEASUREMENT OF SPECTRAL RADIANCE RESPONSIVITY

We are developing a pulsed laser-based uniform source facility for measurement of spectral radiance responsivity. By using an optical parametric oscillator, a wide wavelength range from 210 nm to 2500 nm can be covered by a single device. Realization of the two basic concepts based on the pulse-to-pulse data acquisition are presented and discussed.

D. Hofer, B.G. Zagar
LASER SPECKLE SIMULATION ON A ROUGH WETTING PROBLEM

Computing numerical approximations of the Huygens-Fresnel principle in three dimensions is a rather time (and hardware) demanding task, but thanks to massive parallelization in GPGPU enabled graphics cards these computations can be sped up considerably. A newly developed software framework is capable to simulate a large portion of wave propagation related problems. It seems suited to generate laser speckle images for various real physical setups which were used to measure the surface roughness of sheet metal or the oil film thickness on top of it. This paper gives a short survey on rough wetting theory, it introduces the core parts of the software, and finally it shows some test cases using apertures and their known Fraunhofer diffraction patterns.

M. Rückwardt, A. Göpfert, K. Anding, M. Schellhorn, E. Reetz, G. Linß
TWO-VIEWING-PLANES-PROJECTION: THE NEW WAY OF MEASURING SPECTACLE FRAMES

Only the two-viewing-planes-projection measuring principle is able to measure each closed spectacle frame. It is the first functional optical principle for this measuring task. All the other frame tracers on the market depend on a tactile measuring principle. They are especially not able to measure the needed ground of the groove in the frame of so called high curved sport frames. Therefore, till now, a two-dimensional measurement of a pattern plane was used instead of measuring the three-dimensional groove.
The two-viewing-planes-projection setup can calculate out of two 90° shifted perspectives of the spectacle frame by a camera system the form and the circumference for the needed eyeglasses – even for sport frames.

Katharina Anding, Daniel Garten, André Göpfert, Matthias Rückwardt, Edgar Reetz, Gerhard Linß
AUTOMATIC PETROGRAPHIC INSPECTION BY USING IMAGE PROCESSING AND MACHINE LEARNING

In this paper we present a method for an automatic inspection of mineral aggregates. Certain components of aggregates can negatively affect the mechanical strength of produced concrete or asphalt as well as cause the destructive alkali silica reaction. The automatic recognition of such aggregates could be successfully implemented by means of image processing and machine learning algorithms. We achieved a total recognition rate of 88% for this very complex recognition problem. Therefore every step in the pattern recognition process has been successfully optimized. In conjunction with the object singularization we achieved a fully automatic testing instrument for petrographic inspection.

Page 695 of 977 Results 6941 - 6950 of 9762