• 한국생산제조학회지
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• 제24권5호
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• pp.496-501
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• 2015

In this study, calibration procedure of power assembly tools is suggested and methods are developed for calculating measurement uncertainty. Fist of all, the calibration of joint simulator bench (JSB) was carried out for maintaining traceability and the uncertainty components of JSB were analyzed. The influences of tool speed, tolerance, temperature and length of the adapter were examined by the torque measurement values through experiments. From this research, credibility for calibration results could be enhanced. This experimental results, being used as an effective tool for calibration of power assembly tools, will provide and improve the accuracy of the use of the power assembly tools.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2004년도 추계학술대회 논문집
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• pp.3-9
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• 2004

The machining parts must be produced within the specification of drawing and those will be able to meet function and efficiency. At that time. it is necessary not only precision machine or machining technique but also the measurement technique is very important. So. the improvement of precise measurement technique is to be joined together at once with improvement of product technique. Finally. he quality and value of the parts are decided by precision measurement. This paper aims to study on he measurement uncertainty when the machined parts are inspected with 3-dimensional coordinate measuring machine. The objectives are to remove an error of measurement and to improve quality and productivity of the mass products.

• 대한기계학회논문집B
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• 제29권10호
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• pp.1130-1138
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• 2005

A national standard system for the petroleum field has been developed to calibrate and test the oil flow meters in Korea. The operating system and the uncertainty of the system were evaluated by the peer reviewers of foreign national metrology institutes in 2002. Since the characteristics of the system might be changed by time, the uncertainty of the system is reevaluated with the consideration of the long term stability of the system. It is found that the system has a relative expanded uncertainty of 0.048 $\%$ in the range of $15\~120\;m^3/h$. According to the uncertainty budget, the uncertainties of the fluid density and the final mass measurement, which are temperature dependent, contribute about $94\%$ of the total uncertainty in the oil flow standard system

• 한국군사과학기술학회지
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• 제13권4호
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• pp.665-672
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• 2010

This paper describes Monte Carlo Simulation(MCS) to assess the uncertainty of dynamic pressure calibrator and the expanded uncertainty results that were compared by GUM approximation and MCS. MCS uncertainties were computed using defining a domain of possible inputs, generating inputs randomly using probability distribution, performing a deterministic computation repeatedly and aggregating the results. It was revealed that the expanded uncertainty between GUM and MCS was different from each other. the expanded uncertainties were 0.5366%, 0.4856%, respectively. MCS is a suitable method for determining the uncertainty of simple and complex measurement systems. It should be more widely used and studied in measurement uncertainty calculations.

• 한국정밀공학회지
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• 제22권4호
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• pp.84-91
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• 2005

We measured the pitch of one-dimensional (ID) grating specimens using a metrological atomic force microscope (M-AFM). The ID grating specimens a.e often used as a magnification standard in nano-metrology, such as scanning probe microscopy (SPM) and scanning electron microscopy (SEM). Thus, we need to certify the pitch of grating specimens fur the meter-traceability in nano-metrology. To this end, an M-AFM was setup at KRISS. The M-AFM consists of a commercial AFM head module, a two-axis flexure hinge type nanoscanner with built-in capacitive sensors, and a two-axis heterodyne interferometer to establish the meter-traceability directly. Two kinds of ID grating specimens, each with the nominal pitch of 288 nm and 700 nm, were measured. The uncertainty in pitch measurement was evaluated according to Guide to the Expression of Uncertainty in Measurement. The pitch was calculated from 9 line scan profiles obtained at different positions with 100 ㎛ scan range. The expanded uncertainties (k = 2) in pitch measurement were 0.10 nm and 0.30 nm for the specimens with the nominal pitch of 288 nm and 700 nm. The measured pitch values were compared with those obtained using an optical diffractometer, and agreed within the range of the expanded uncertainty of pitch measurement. We also discussed the effect of averaging in the measurement of mean pitch using M-AFM and main components of uncertainty.

• 분석과학
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• 제26권2호
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• pp.125-134
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• 2013

본 연구는 액체크로마토그래피를 이용하여 사골농축액 시료 중에 23종의 아미노산 정량분석 시 발생할 수 있는 측정불확도를 평가하였다. 아미노산 분석에 관여하는 측정불확도 인자로 시료량, 최종 무게, 표준품 무게, 표준품 순도, 검정곡선, 회수율 및 재현성 등을 확인하였다. GUM(Guide to the expression of uncertainty in measurement)과 EURACHEM에 근거하여 측정불확도에 대한 수학적 계산 및 통계분석을 수행하였다. 사골농축액 시료 중 총 아미노산 함량은 36.18 g/100 g이었으며, 95% 신뢰수준(k, 2.05~2.36)에서 확장불확도는 3.81 g/100 g이었다. 측정불확도의 주요 요인은 분석시의 회수율과 반복성(25.2%) > 시료전처리(24.5%) > 검정곡선(24.0%) 순으로 나타났다. 따라서 아미노산 분석 시 불확도를 줄이기 위해서는 실험자들의 주의와 개인적인 숙력도의 향상이 요구된다.

• Ocean and Polar Research
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• 제36권1호
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• pp.77-85
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• 2014

The quality control of ocean observations data is becoming a major issue as real-time observational data and information services have increased recently. Therefore, it is necessary for oceanographic instruments to calibrate. In this paper, we first introduce the CTD calibration system and traceability. Next, CTD calibration procedures and estimation of uncertainty of measurement are described. The expanded uncertainty (k = 2) of the temperature, pressure and conductivity are 0.$0.003^{\circ}C$, $6.0{\times}10^{-5}$ and 0.006 mS/cm respectively. Finally, the excellence of CTD calibration and its measurement capability has been proven by comparing the inter-calibration result of KIOST and Sea-Bird Electronics (SBE). CTD calibration residuals are less than ${\pm}0.0001^{\circ}C$, ${\pm}0.001$ MPa, ${\pm}0.0001$ S/m for SBE 3plus temperature sensor, SBE 19plus pressure sensor and SBE 4C conductivity sensor respectively.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.264-267
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• 2003

Pitch measurements of 150 nm pitch one-dimensional grating standards were carried out using an contact mode atomic force microscopy(C-AFM) with a high resolution three-axis laser interferometer. It was called as 'Nano-metrological AFM' In Nano-metrological AFM, Three laser interferometers were aligned well to the end of AFM tip. Laser sources of the three-axis laser interferometer in the nano-metrological AFM were calibrated with an I$_2$-stablilzed He-Ne laser at a wavelength of 633 nm. So, the Abbe error was minimized and the result of the pitch measurement using the nano-metrological AFM has a traceability to the length standard directly. The uncertainty in the pitch measurement was estimated in accordance with the Guide to the Expression of Uncertainty in Measurement(GUM). The Primary source of uncertainty in the pitch-measurements was derived from repeatability of pitch-measurement, and its value was approx 0.186 nm. Expanded uncertainty(k=2) of less than 5.23 nm was obtained. It is suggested that the metrological AFM is a useful tool for the nano-metrological standard calibration.

• 한국정밀공학회지
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• 제26권8호
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• pp.72-78
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• 2009

We developed a line standards measurement system using an optical microscope and measured two kinds of line standards. It consists of three main parts: an optical microscope module including a CCD camera, a stage system with a linear encoder, and a measurement program for a microscopic image processing. The magnification of microscope part was calibrated using one-dimensional gratings and the angular motion of stage was measured to estimate the Abbe error. The threshold level in line width measurement was determined by comparing with certified values of a line width reference specimen, and its validity was proved through the measurement of another line width specimen. The expanded uncertainty (k=2) was about 100 nm in the measurements of $1{\mu}m{\sim}10{\mu}m$ line width. In the comparison results of line spacing measurement, two kinds of values were coincide within the expanded uncertainty, which were obtained by the one-dimensional measuring machine in KRISS and the line standards measurement system. The expanded uncertainty (k=2) in the line spacing measurement was estimated as $\sqrt{(0.098{\mu}m)^2+(1.8{\times}10^{-4}{\times}L)^2}$. Therefore, it will be applied effectively to the calibration of line standards, such as line width and line spacing, with the expanded uncertainty of several hundreds nanometer.

• 대한조선학회논문집
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• 제51권5호
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• pp.396-408
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• 2014

In this study, uncertainty analysis based on ITTC(International Towing Tank Conference) Recommended Procedures is carried out in the towing-tank experiment for motion responses and added resistance. The experiment was conducted for KVLCC2 model in head sea condition. The heave, pitch and added resistance were measured in different wave conditions, and the measurement was repeated up to maximum 15 times in each wave condition in order to observe the uncertainty of measured data. The uncertainty analysis was carried out by adopting the ISO-GUM(International Organization for Standardization, Guide to the Expression of Uncertainty in Measurements) method recommended by ITTC. This paper describes the details about the analysis method, uncertainty and the measured uncertainty for each source. The uncertainty analysis results are summarized as a tabular form. To validate the accuracy of the present measurement, the experimental results are compared with the results of numerical computation and other experiment. From the present uncertainty analysis, the main sources of uncertainty are identified, which can be very useful to improve the accuracy for added resistance experiment.