• 대한안전경영과학회지
• /
• 제9권1호
• /
• pp.145-156
• /
• 2007

This paper is to propose model classification and evaluation of measurement uncertainty. In order to obtain type A and B uncertainty, variety of measurement mathematical models are illustrated by example. The four steps to evaluate expanded uncertainty are indicated as following; First, to get type A standard uncertainty, measurement mathematical models of single, double, multiple, design of experiment and serial autocorrelation are shown. Second, to solve type B standard uncertainty measurement mathematical models of empirical probability distributions and multivariate are presented. Third, type A and B combined uncertainty, considering sensitivity coefficient, linearity and correlation are discussed. Lastly, expanded uncertainty, considering degree of freedom for type A, B uncertainty and coverage factor are presented with uncertainty budget. SPC control chart to control expanded uncertainty is shown.

• 품질경영학회지
• /
• 제51권3호
• /
• pp.419-434
• /
• 2023

Purpose: Measurement results obtained under non-ideal measurement environment conditions may contain uncertain factors. As a result, the reliability of measurement results may be deteriorated. In this study, we tried to find ways to improve quality by evaluating and applying measurement uncertainty based on GUM. Methods: In the flatness measurement of semiconductor parts, uncertainty factors that could occur under actual environmental conditions of workers were derived, and measurement uncertainties were calculated, and methods for minimizing the main factors affecting the measurement results were analyzed. Results: Depending on the part and the coordinate measuring machine, it was shown that the effect of dispersion caused by repeated measurements as type A uncertainty and the effect of the calibration results of equipment as type B uncertainty have the main influence. Conclusion: Depending on the uncertainty factors of type A and type B and the influence of the total expanded uncertainty, the central value and confidence interval of the initial measurement results showed fluctuations. It is considered that analysis and measures for the main uncertainty factors are needed as quality improvement in the industrial field.

• Corrosion Science and Technology
• /
• 제8권5호
• /
• pp.193-196
• /
• 2009

For the estimation of uncertainty in potentiodynamic polarization resistance measurement, the type A uncertainty was measured using type 316 stainless steel in an acidified NaCl solution. Sensitivity coefficients were determined for measurand such as scan rate of potential, temperature of solution, concentration of NaCl, concentration of HCl, surface roughness of specimen and flow rate of purging gas. Sensitivity coefficients were large for the measurand such as the scan rate of potential, temperature of solution and roughness of specimen. However, the sensitivity coefficients were not the major factors influencing the combined standard uncertainty of polarization resistance due to the low values of uncertainty in measurements of the measurands. A major influencing factor was the concentration of NaCl. The value of type A uncertainty was 1.1 times the value of type B uncertainty, and the combined standard uncertainty was 10.5 % of the average value of polarization resistance.

• 전기학회논문지
• /
• 제67권6호
• /
• pp.724-729
• /
• 2018

This paper presented an evaluation method for the efficiency uncertainty of an inverter-fed three-phase induction motor using FEM. The motor efficiency in the FEM is calculated by the IEC 60034-2-3 as in the actual test. In the process of evaluating the efficiency uncertainty, the difference between the finite element method and the actual test is the method of calculating the type-A / B standard uncertainty of the input quantity to estimate the efficiency and each losses. For the input quantities which can confirm the instantaneous values with respect to time, the type-A standard uncertainty in the FEM is calculated from the RMS values or average values having separate periods in the steady state. And, the type-B standard uncertainty in the finite element method is assumed to be zero. Also, this paper compared and analyzed the efficiency uncertainty evaluated by the proposed method and the efficiency uncertainty through the actual test.

• 전기학회논문지P
• /
• 제66권4호
• /
• pp.163-168
• /
• 2017

This paper presented an evaluation method for the efficiency uncertainty of a three-phase induction motor using finite element analysis. The motor efficiency in the finite element analysis is calculated by the loss separation method as in the actual test. In the process of evaluating the efficiency uncertainty, the difference between the finite element analysis and the actual test is the method of calculating the type-A / B standard uncertainty of the input quantity to estimate the efficiency and each losses. For the input quantities which can confirm the instantaneous values with respect to time, the type-A standard uncertainty in the finite element analysis is calculated from the RMS values or average values having separate periods in the steady state. And, the type-B standard uncertainty in the finite element analysis is assumed to be zero. Also, this paper compared and analyzed the efficiency uncertainty evaluated by the proposed method and the efficiency uncertainty through the actual test.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 1997년도 춘계학술대회 논문집
• /
• pp.68-72
• /
• 1997

This paper presents the design and the evaluation of the 6-component force/moment calibration machine which h a s t h e maximum capacities of 500 N in forces and 50 Nm in moments. This calibration machine consists of body. fixture. force generating system, moment generating system. The expanded uncertainty of the calibration machine is evaluated by calculating the A type uncertainty. $U_A$ and B type uncertainty, $U_B$. The evaluation results. this system has the expanded uncertainty of less than $2{\times}10^[-2]$ in respective force and moment components.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2000년도 춘계학술대회논문집
• /
• pp.1675-1680
• /
• 2000

Recently the uncertainty has been made rapid progress in various fields of industry but the uncertainty measurement method of acoustical test (i.e. Insertion loss, Absorption ratio, Transmission loss etc,) hasn't been established. In this study, the uncertainty of measurement method for ducted silencers is carried out according to ISO 7235. The standard uncertainty factors are composed of sound pressure level, microphone sensitivity and pistonphone calibration in this measurement. Sound pressure level is type A evaluation of uncertainty, microphone sensitivity and pistonphone calibration are type B evaluation of uncertainty. The combined standard uncertainty is calculated by two type evaluation. The expanded uncertainty is expressed by the combined standard uncertainty multiply k value which is yield the effective degree of freedom.

• 한국대기환경학회지
• /
• 제17권4호
• /
• pp.313-319
• /
• 2001

The development of ozone SRP (Standard Reference Photometer) designated as a G-7 project by the Korean Ministry of Environment began 1997 and is now nearly completed. With the completion of the ozone SRP we will not only acquire a qualification to participate in the international ozone calibration system but also enhance calibration credibility of ozone similarly to that of other ambient air pollution monitors. As the ozone SRP uses highly cleaned blank air that can be distinguished from general ozone analyzer, it is possible to reduce errors associated with the determination of ozone via elongation of the absorption length as long as 1 meter In addition, gas chopping method hat been adopted to cut down interference of other substances and time drift. Furthermore, the system has also been modified to minimize the strayed ultra-violet noise along the light path. In this paper, a new method for uncertainty evaluation has been introduced, which is guided by the ISO (International Standard Organization) GUM (Guide to the Expression of Uncertainty in Measurement) through assessments of the uncertainty type B (that was impossible to estimate before) as well as the uncertainty type A (based on statistics).

• 한국소음진동공학회논문집
• /
• 제26권7호
• /
• pp.781-786
• /
• 2016

All measurements are subject to uncertainty and a measurement result is complete only when it is accompanied by a statement of the associated uncertainty. By international agreement, this uncertainty has a probabilistic basis and reflects incomplete knowledge of the quantity value. The "Guide to the Expression of Uncertainty in Measurement", commonly known as the GUM, is the definitive document on this subject. The requirements for estimation of measurement uncertainty apply to all results provided by calibration laboratories and results produced by testing laboratories under the optional circumstances. In this paper, a procedure for estimation of measurement uncertainty from vibration testing is proposed on KS F 2868:2003 as an example. Both Type A and Type B evaluation of uncertainty are considered to calculate the combined standard uncertainty and expanded uncertainty.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2003년도 추계학술대회 논문집(III)
• /
• pp.301-306
• /
• 2003

Recently, uncertainty of measurement became a major concern for the people working on the laboratory evaluation and accreditation. 'uncertainty of measurement is a parameter associated with the result of a measurement that characteristics the dispersion of the value that could reasonably be attributed to the measured.' This study analysed how to estimate uncertainty of measurement in mechanical characteristic exam for Plastic material. its uncertainty was estimated according to International Organization for Standardization(ISO), they were named to A type uncertainty, B type uncertainty, combined standard uncertainty, and expanded uncertainty. We obtained that the combined standard uncertainty was 0.96697 MPa and the expanded uncertainty was 2.291MPa.