• 오토저널
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• 제10권3호
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• pp.31-37
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• 1988

A phase different method to evaluate the instrument error of roundness measuring instrument and the form error of specimens for the calibration of the instrument is used. An instrument with a rotary table supported by an air bearing was calibrated by using the standard balls as a standard. The calibration was carried out repeatedly by setting the same ball in 12 phase angles(per 30.deg.) on the table and by recording their roundness errors with a magnification of 100,000 times. As a result of data analysis of all the observations, readout at each of 144 orientations(per 2.5.deg.) from recorded data file, the error of performance of the instrument and the specimens are separated. In the particular instrument used in the present experiment, the error of the instrument was determined with the accuracy of 0.0164 (.mu.m) and the form error of the specimens was determined with the accuracy of 0.0264,0.0172(.mu.m), respectively. If the instrument was calibrated by using the above specimens, then the accuracy of the measurement of roundness error can be improved to about 0.017 (.mu.m).

• 대한기계학회논문집
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• 제13권5호
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• pp.862-874
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• 1989

본 연구에서는 반경법 진원도 측정기의 회전정도와 편심에 의한 영향을 제거 하여 시험편의 형상오차와 측정기 자체의 오차특성을 분리함으로써 진원도 측정의 정도를 향상시킬 수 있는 방법에 대하여 검토하였다. 진원도의 표시법으로는 최근 최소영역법에 의해 규정되는 경우가 많으나 이는 일반적으로 많은 연산시간을 요구 하므로 비경제적인 면이 있다.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제54권2호
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• pp.66-70
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• 2005

Linearity of ratio error of instrument transformer comparator has been tested using wide ratio error voltage transformer(VT) with the ratio errors in the range of -3 ％ to 3 ％. The technique is the method for evaluation of the linearity for instrument transformer comparator by comparing both the theoretical and experimental values in wide ratio error VT. The developed method has been successfully applied for calibration and correction in instrument transformer comparator belonging to industry.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.760-761
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• 2007

Instrument transformers provide the reproduction of the primary current or voltage to the measuring and protecting devices. The errors of an iron-cored transformer are caused by the difference between the primary and secondary currents due to the hysteresis characteristics of the iron-core. An error compensating algorithm for instrument transformer can improve the accuracy of conventional current and voltage transformers. This paper describes the performances of the electronic current and voltage transformers mounted an error compensating algorithm. The test results of the electronic transformers in Korea Electrotechnology Research Institute(KERI) are presented.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.355-356
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• 2006

This paper proposes an Molding error compensation method that improves accuracy with geometry information of injected parts using three-dimensional measuring instrument. a traditional mold design has been conducted by an experience-based trial and error, whereby generally the mold designer would decide the gate location and processing conditions. as a natural consequence, almost all creats inferior goods. It's just a process of trial and error and caught in a vicious circle. Due to this reason, this paper uses a three-dimensional measuring instrument, a commercial analysis package of injection molding(Moldflow, MPI) to analysis a state of flux. In addition to that axiomatic approach.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2004년도 춘계학술발표회논문집
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• pp.83-89
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• 2004

The electronic distance measurement instrument, first introduced in the 1950s has, since those early days, undergone continual refinement. Rapid advances in related technologies have provided lighter, smaller and more precise equipment. Understanding for the principle, the standardized observation technique and the precision of EDM instrument is mostly important to improve the quality and the reliability of by-product in the field of engineering and industrial surveying. Simple and accurate calibration is regularly and periodically necessary to maintenance the precision of EDM instrument. This paper describes the calculated example of zero error and scale error as a correction of EDM by applying the least square method to baseline observations. Here we deals also with the testing criteria for precision instrument testing according to different types of EDM instruments.

• 한국측량학회지
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• 제22권2호
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• pp.137-143
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• 2004

EDM 기계는 1950년대 최초로 소개된 이후 전자 및 광학기술의 발전에 힘입어 소형화, 고정밀화 됨으로써 현재에는 측량뿐만 아니라 정밀 과학 계측 분야에서까지 널리 활용되고 있다. EDM 기계에 대한 원리의 이해 및 표준화된 관측 방법에 대한 이해와 더불어 정밀도에 대한 이해는 측정 결과의 신뢰성 향상 및 산업측량, 시공측량 등의 활용 분야에 있어서 2차적인 생산물의 품질 향상을 위해서 매우 중요하다 할 수 있다. 이러한 EDM 기계의 정밀도 유지를 위해서 규칙적이고 주기적인 점검이 이루어져야 하며, 단순하면서도 정밀한 점검 방법이 요구된다. 본 논문에서는 기선거리 관측 데이터로부터 최소자승법을 이용하여 간단하게 EDM 기계의 보정계수인 영점오차와 축척오차를 동시에 결정하는 방법을 제시하였고 산정된 보정계수를 이용하여 EDM 기계의 정밀도에 따른 검교정을 위한 검정 방법을 제시하였다.

• 한국환경과학회지
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• 제11권10호
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• pp.1055-1060
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• 2002

A new method of automatic recording raingauge is developed to measure rainfall 1200mm full scale with high accuracy and resolution. The principle of new instrument is to detect a weight change of a buoyant weight according to a change in water level of raingauge measured by the use of a strain gauge load cell. This method has the advantage of increasing measurement accuracy, since no moving equipment is used. Laboratory test of the instrument was recorded 0.4% error of 190mm rainfall amount. The validity of new instrument was examined by comparing its measured values with values recorded by automatic weather station on June 24 to 25 2001 at Daegu Meteorological Station, when there is 148.3mm rainfall amount. In spite of much rainfall there is only 0.77mm difference of total rainfall amount. This instrument was accomplished high accuracy and resolution at field test in much rainy day.

• Current Optics and Photonics
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• 제7권4호
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• pp.387-397
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• 2023

Tooth surface shape error is an important parameter in gear accuracy evaluation. When tooth surface shape error is measured by laser interferometry, the gear interferogram is highly distorted and the gray level distribution is not uniform. Therefore, it is important for gear interferometry to extract the foreground region from the gear interference fringe image directly and accurately. This paper presents an approach for foreground extraction in gear interference images by leveraging the sinusoidal variation characteristics shown by the interference fringes. A gray level mask with an adaptive threshold is established to capture the relevant features, while a local variance evaluation function is employed to analyze the fluctuation state of the interference image and derive a repair mask. By combining these masks, the foreground region is directly extracted. Comparative evaluations using qualitative and quantitative assessment methods are performed to compare the proposed algorithm with both reference results and traditional approaches. The experimental findings reveal a remarkable degree of matching between the algorithm and the reference results. As a result, this method shows great potential for widespread application in the foreground extraction of gear interference images.

• Journal of Astronomy and Space Sciences
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• 제31권3호
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• pp.241-246
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• 2014

The Amon-Ra instrument is the main optical payload of the proposed EARTHSHINE satellite. It consists of a visible wavelength instrument and an IR energy channel instrument to measure a global Earth albedo. We report a new sensitivity technique for efficient alignment of the visible channel instrument. Whilst the sensitivity table method has been widely used in the alignment process, the straightforward application of the method tends to produce slow process convergence because of shop floor alignment practice uncertainties. We investigated the error sources commonly associated with alignment practices and used them when estimating the Zernike polynomial coefficients. Aided with single center field wavefront error (WFE) measurements and their corresponding Zernike polynomial coefficients, the method involves the construction and use of an experimental, instead of simulated, sensitivity table to be used for alignment state estimations. A trial alignment experiment for the Amon Ra optical system was performed and the results show that 71.28 nm in rms WFE was achieved only after two alignment iterations. This tends to demonstrate its superior performance to the conventional method.