Chao-Ching Ho, Chih-Mu Chiu, Yuan-Jen Chang, Jin-Chen Hsu, Chia-Lung Kuo
This paper presents a novel method for controlling the laser-drilling process for a hole by monitoring induced plasma emission. The variation of light brightness from laser-induced plasma is used as an indicator to control laser percussion drilling. Through on-line plasma emission acquisition and analysis, we obtain the positive association between the increased depth and the optical signal output. A coaxial photodiode is used to estimate the brightness levels of laser-induced plasma. The above constitute an inexpensive and practical on-line feedback system that can be easily implemented in...
TC14 LMPMI Symposium 2014
· TC14
· 2014
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Thanh Tung Vu, Yoshitaka Maeda, Masato Aketagawa
A displacement measurement with an uncertainty of less than sub-nanometer is required in many industrial fields. A laser interferometer has become a powerful tool in nano-metrology, because the wavelength of the light source can be calibrated by meter definition. In this paper, we propose the use of sinusoidal phase (frequency) modulation on a laser diode (LD) to achieve both the frequency stabilization of the LD and a displacement measurement by a homodyne interferometer.
TC14 LMPMI Symposium 2014
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· 2014
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Hu Lin, Zi Xue, Guoliang Yang, Yao Huang, Heyan Wang
A specialized high accurate gear artifact measuring instrument based on laser interferometry is developed in National Institute of Metrology (NIM, China), to fulfill the increasing demand for high accurate calibration of gear artifacts. This measuring instrument mainly consists of three linear guide rails, a rotary table, a 3D scanning probe and a laser measuring system. In the laser measuring system, laser beam from laser head is splited along two paths, one is arranged tangent to the base circle of gear for the measurement of profile deviation, another is arranged parallel to the gear axis...
TC14 LMPMI Symposium 2014
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· 2014
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Junichiro Kitta, Agustinus Winarno, Kazuo Tomiyama, Tomizo Kurosawa
This paper aims at improving an optical interferometer for gauge block calibration. Gauge block calibration technique by using optical interferometric method is considered as an ultimate calibration method because of it enables absolute calibration, high accuracy and ensures direct traceability to the definition of length. Therefore, national institute of metrology, calibration laboratory organization or manufactures of gauge block often adopt this optical interferometric method. We describe introducing iodine stabilized 532 nm Nd:YAG laser, rubidium stabilized 780 nm Nd:YLF laser and offset...
TC14 LMPMI Symposium 2014
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Eugen Trapet
The use of optical systems for the dimensional inspection in industrial production (e.g. automotive, aeronautic) is steadily increasing. However, a thorough performance verification of such systems must still become more popular; now international standards have been published and the habit of verification may improve. The presentation will introduce to the key elements of prevailing standards. The basic rules for performance verification of Video CMMs and CMMs with fringe projection sensors and laser scanners, stand alone fringe projection and scanner systems will be discussed. In order to...
TC14 LMPMI Symposium 2014
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Tatsuya Kume, Kazuhiro Enami, Yasuo Higashi, Kenji Ueno, Masashi Yamanaka
Straightness evaluation using 3-point method has an advantage for evaluating large objects being not affected by straightness references; however, error introduced by each measurement and propagating to the derived straightness should also be taken into account for evaluating large objects. In this paper, errors propagated to the straightness derived by 3-point method were estimated analytically based on error propagating models and the estimated errors were evaluated by experiments. The results show that each longitudinal positioning error for the straightness detector should be considered...
TC14 LMPMI Symposium 2014
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· 2014
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Yohan Kondo, Youichi Bitou, Osamu Sato, Makoto Abe
Flick standard is a cylindrical artifact with a flat part for calibrating the magnification of a probe of roundness measuring-instruments. A probe magnification of roundness measuring-instruments is evaluated by measuring a calibrated flick value of a flick standard. The flick value is a distance between a cross-section circle and a cross-section line. In factory field, it is required that the flick value is calibrated within 0.1 µm with respect to several micrometer to several hundred micrometer. The flick value is generally calibrated by an accurate roundness measuring-instrument. It has a...
TC14 LMPMI Symposium 2014
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Steffen Matthias, Markus Kastner, Eduard Reithmeier
In this paper, we present a method of an accurate camera and projector calibration for a newly developed endoscopic micro fringe projection system. The system consists of a laser illuminated digital micro-mirror device (DMD) for the projection of arbitrary structured light patterns, such as Gray code and cos²-phaseshift patterns. These patterns are focused into a 100’000 pixel image fiber and at the endpoint projected onto the specimen via gradient index lenses. A similar fiber assembly guides the perspective-distorted patterns back from the measurement object to a CCD-camera. The design for...
TC14 LMPMI Symposium 2014
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Yasushi Azuma, Kenji Odaka, Akira Kurokawa, Toshiyuki Fujimoto
X-ray reflectometry (XRR) is a powerful tool for the structural characterization of thin films. However the standardized protocols of the measurements and their analyses need to be established for the reliable and reproducible characterization. The collaborative work between National Institute of Standards and Technology (NIST, USA) and National Metrology Institute of Japan (NMIJ, Japan) for thickness evaluation by XRR has been carried out in order to support the activities for the standardization of the thickness evaluation. In order to evaluate the accurate thickness of thin film...
TC14 LMPMI Symposium 2014
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Kazuhiko Kawasaki, Shinichiro Yanaka, Kaoru Miyata, Hajime Inaba, Feng-Lei Hong
We developed an optical frequency comb system (the Mitutoyo comb) synchronized to a rubidium (Rb) based frequency standard oscillator which is linked to the Coordinated Universal Time (UTC) operated by the National Metrology Institute of Japan (NMIJ). We measured the frequency of an iodine stabilized laser at 532 nm which is listed as a wavelength standard for length applications. The frequency measurement results taken by the Mitutoyo comb was compared with the results using another frequency comb system developed by NMIJ (the NMIJ comb). When a common laser frequency was measured by the...
TC14 LMPMI Symposium 2014
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· 2014
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