• Title/Summary/Keyword: Calibration standard tube

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Characteristic Analysis of Eddy Current Array Probe Signal in Combo Calibration Standard Tube Using Electromagnetic Numerical Analysis (전자기 수치해석을 이용한 표준보정시험편의 배열형 와전류 탐촉자 신호 특성 해석)

  • Kim, Ji-Ho;Lee, Hyang-Beom
    • Journal of the Korean Society for Nondestructive Testing
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    • v.30 no.4
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    • pp.330-337
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    • 2010
  • In this paper, 3-dimensional electromagnetic numerical analysis is performed about the eddy current(EC) array probe characteristic which is the next generation probe for accurate diagnosis of steam generator(SG) in nuclear power plants(NPPs). ASME(American Society of Mechanical Engineers) Standard and X-probe combo calibration standard tube are selected for acquisition of eddy current testing(ECT) signals and this result of compared with the real test signals for reasonability of result. Based on the analysis result of calibration standard tube, ECT signals that are about the defects of pitting, stress corrosion cracking(SCC), multiple SCC and wear is obtained. Material of specimen was Inconel 600 which is usually used for SG tubes in NPPs. The operation frequency of 300 kHz were used. The signal characteristics could be observed according to the various defects. The results in this paper can be helpful when the ECT signals from EC array probe are evaluated and analyzed.

Simulation and Evaluation of ECT Signals From MRPC Probe in Combo Calibration Standard Tube Using Electromagnetic Numerical Analysis (전자기 수치 해석을 이용한 Combo 표준 보정 시험편의 MRPC Probe 와전류 신호 모사 및 평가)

  • Yoo, Joo-Young;Song, Sung-Jin;Jung, Hee-Jun;Kong, Young-Bae
    • Journal of the Korean Society for Nondestructive Testing
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    • v.26 no.2
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    • pp.90-98
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    • 2006
  • Signals captured from a Combo calibration standard tube paly a crucial role in the evaluation of motorized rotating pancake coil (MRPC) probe signals from steam generator (SG) tubes in nuclear power plants (NPPs). Therefore, the Combo tube signals should be consistent and accurate. However, MRPC probe signals are very easily affected by various factors around the tubes so that they can be distorted in their amplitudes and phase angles which are the values specifically used in the evaluation. To overcome this problem, in this study, we explored possibility of simulation to be used as a practical calibration tool far the evaluation of real field signals. For this purpose, we investigated the characteristics of a MRPC probe and a Combo tube. And then using commercial software (VIC-3D) we simulated a set of calibration signals and compared to the experimental signals. From this comparison, we verified the accuracy of the simulated signals. Finally, we evaluated two defects using the simulated Combo tube signals, and the results were compared with those obtained using the actual field calibration signals.

An Experimental Study on the Influential Factors of Flow Measurement with Coriolis Mass Flowmeter (코리올리스 질량유량계의 유량측정에 영향을 미치는 인자에 관한 실험적 연구)

  • Lim, Ki-Won;Lee, Woan-Kyu
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.27 no.12
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    • pp.1699-1707
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    • 2003
  • Coriolis mass flowmeter(CMF), which can measure the mass flow directly, is getting rapid attention for the industrial and custody transfer purpose. In order to study the characteristics and the applicability of CMF, it is tested with the national flow standard system. Two types of sensing tube, U-type and straight type, are employed in the test. Water, spindle oil and viscosity Standard Reference Material whose viscosities are 1, 20 and, 67 $\textrm{mm}^2$/s, respectively, are studied. It is shown that the linearity of CMF is getting deteriorated as the fluid viscosity increases, which is due to the zero drift and the relaxation time of the fluid. To test its applicability in the case of high pressured gas, it is calibrated using compressed air, It shows 1∼l.6 % deviations compared to the calibration results using water. It concludes that the fluid velocity in CMF should be lower than the sonic velocity. In addition, the effects of the vibration from the pipeline and pump on CMF as well as the long term stability are studied.

Simulation of Eddy Current Testing Signals Using Simulation Software Dedicated to Nondestructive Testing (비파괴검사 전용 시뮬레이터를 이용한 와전류검사 신호 시뮬레이션)

  • Lee, Tae-Hun;Cho, Chan-Hee;Lee, Hee-Jong
    • Transactions of the Korean Society of Pressure Vessels and Piping
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    • v.10 no.1
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    • pp.75-81
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    • 2014
  • A simulation of eddy current testing has been utilized for predicting the signal characteristics to the various defects and developing the probes. Especially, CIVA which is a simulation tool dedicated to nondestructive testing has a good accuracy and speed, and provides a three-dimensional graphical user interface for improved visualization and familiar data displays consistent with NDE technique. Although internal validations have been performed by the CIVA software development specialists, an independent validation study is necessary for the accuracy assessment of the software prior to practical use. For this purpose, in this study, eddy current testing signals of ASME FBH calibration standard tube for bobbin probe were simulated using CIVA and the results were compared to the experimental inspected signals based on the relationship between each flaw signal in terms of amplitude and phase, and the shape of the Lissajous curve. And then we verified the accuracy of the simulated signals and the possible range for simulation. Overall, there is a good qualitative agreement between the CIVA simulated and experimental results in the absolute and differential modes at the two inspection frequencies.

Development of a Method to Measure Hydrogen Sulfide in Wine Fermentation

  • Park, Seung-Kook
    • Journal of Microbiology and Biotechnology
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    • v.18 no.9
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    • pp.1550-1554
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    • 2008
  • A hydrogen sulfide $(H_2S)$ detecting tube was developed for the quantitative determination of $H_2S$ produced by yeast during laboratory scale wine fermentations. The detecting tube consisted of a small transparent plastic tube packed with an $H_2S$-sensitive color-indicating medium. The packed medium changed color, with the color change progressing upward from the bottom of the tube, upon exposure to $H_2S$ produced by yeast during fermentation. A calibration study using a standard $H_2S$ gas showed that the length of the portion that darkened was directly related to the quantity of $H_2S$ (${\mu}g$) with a high correlation coefficient ($r^2$=0.9997). The reproducibility of the $H_2S$ detecting tubes was determined with five repetitive measurements using a standard $H_2S$ solution [5.6${\mu}g$/200 ml (28 ppb)], which resulted in a coefficient of variation of 3.6% at this level of $H_2S$. With the sulfide detecting tubes, the production of $H_2S$ was continuously monitored and quantified from laboratory scale wine fermentations with different yeast strains and with the addition of different levels of elemental sulfur to the grape juice. This sulfide detecting tube technology may allow winemakers to quantitatively measure $H_2S$ produced under different fermentation conditions, which will eventually lead winemakers to better understand the specific factors and conditions for the excessive production of $H_2S$ during wine fermentation in a large production scale.

Development of Remote Reld Testing Technique for Moisture Separator & Reheater Tubes in Nuclear Power Plants (원자력발전소 습분분리재열기 튜브 원격장검사 기술 개발)

  • Nam, Min-Woo;Lee, Hee-Jong;Kim, Cheol-Gi
    • Journal of the Korean Society for Nondestructive Testing
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    • v.28 no.4
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    • pp.339-345
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    • 2008
  • The heat exchanger tube in nuclear power plants is mainly fabricated from nonferromagnetic material such as a copper, titanium, and inconel alloy, but the moisture separator & reheater tube in the turbine system is fabricated from ferromagnetic material such as a carbon steel or ferrite stainless steel which has a good mechanical properties in harsh environments of high pressure and temperature. Especially, the moisture separator & reheater tubes, which use steam as a heat transfer media, typically employ a tubing with integral fins to furnish higher heat transfer rates. The ferromagnetic tube typically shows superior properties in high pressure and temperature environments than a nonferromagnetic material, but can make a trouble during the normal operation of power plants because the ferrous tube has service-induced damage forms including a steam cutting, erosion, mechanical wear, stress corrosion cracking, etc. Therefore, nondestructive examination is periodically performed to evaluate the tube integrity. Now, the remote field testing(RFT) technique is one of the solution for examination of ferromagnetic tube because the conventional eddy current technique typically can not be applied to ferromagnetic tube such as a ferrite stainless steel due to the high electrical permeability of ferrous tube. In this study, we have designed RFT probes, calibration standards, artificial flaw specimen, and probe pusher-puller necessary for field application, and have successfully carry out RFT examination of the moisture separator & reheater tube of nuclear power plants.

Development of Small Size Coriolis Mass Flowmeter (소형 코리올리 질량 유량계의 개발)

  • Lim Ki-Won;Ji Jueng-Keun
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.30 no.6 s.249
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    • pp.497-504
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    • 2006
  • A Coriolis mass flowmeter(CMF), which has U-Shaped unique measurins tube was developed fo. direct mass flow measurement. In order to convert the time difference between two measuring tubes motion into mass flowrate and flow quantity, a signal processing circuit, as a part of CMF, was also developed. The CMF was designed as the 15 mm nominal diameter of pipe connection and the 8 mm stainless steel(sus 316) pipe was used for measuring tube. To maximize the flow signal(time difference) from the measuring tubes, the natural frequency of measuring tube was adjusted as 220 Hz, which is same as the frequency of exciter. The maximum displacement at the end of the measuring tube was measured as 0.05 mm and the maximum time difference between two measuring tubes was observed as $20{\mu}s$, which was proper for discrimination and measuring range of CMF. The developed CMF was tested against the gravimetric flowmeter calibrator in the range of 3 kg/min and 30 kg/min. The results showed that the CMF has good linearity and repeatability in the tested flow range. Large size of CMF base on the current study experience will be developed.

IMPLEMENTATION OF DATA ASSIMILATION METHODOLOGY FOR PHYSICAL MODEL UNCERTAINTY EVALUATION USING POST-CHF EXPERIMENTAL DATA

  • Heo, Jaeseok;Lee, Seung-Wook;Kim, Kyung Doo
    • Nuclear Engineering and Technology
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    • v.46 no.5
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    • pp.619-632
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    • 2014
  • The Best Estimate Plus Uncertainty (BEPU) method has been widely used to evaluate the uncertainty of a best-estimate thermal hydraulic system code against a figure of merit. This uncertainty is typically evaluated based on the physical model's uncertainties determined by expert judgment. This paper introduces the application of data assimilation methodology to determine the uncertainty bands of the physical models, e.g., the mean value and standard deviation of the parameters, based upon the statistical approach rather than expert judgment. Data assimilation suggests a mathematical methodology for the best estimate bias and the uncertainties of the physical models which optimize the system response following the calibration of model parameters and responses. The mathematical approaches include deterministic and probabilistic methods of data assimilation to solve both linear and nonlinear problems with the a posteriori distribution of parameters derived based on Bayes' theorem. The inverse problem was solved analytically to obtain the mean value and standard deviation of the parameters assuming Gaussian distributions for the parameters and responses, and a sampling method was utilized to illustrate the non-Gaussian a posteriori distributions of parameters. SPACE is used to demonstrate the data assimilation method by determining the bias and the uncertainty bands of the physical models employing Bennett's heated tube test data and Becker's post critical heat flux experimental data. Based on the results of the data assimilation process, the major sources of the modeling uncertainties were identified for further model development.

Eddy Current and Ultrasonic IRIS Signal Characteristics of Reboiler Tube by Using STS 316L Calibration Specimen (STS 316L 교정시험편을 이용한 재가열기 튜브의 와전류신호와 초음파 IRIS 신호 특성)

  • Tak, Kyeong-Joo;Kim, Byung-Il;Gook, Jin-Seon
    • Journal of the Korean Society for Nondestructive Testing
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    • v.32 no.1
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    • pp.56-63
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    • 2012
  • In this study, a field applicability of reboiler tube was evaluated by comparing ECT signal with IRIS signal about wall loss rate and remaining wall thickness using worked austenite STS 316L ASME standard calibration tube. In the case of wall-loss rate, as a result, tolerance about $20%{\times}4$ flat bottom hole and 10% O D groove(ECT), 80% defect and 10% O D groove(IRIS) occurred up to ${\pm}15%$. In the case of remaining wall thickness, ECT was satisfied with the both tolerance, but tolerance about 80% defect occurred up to ${\pm}15%$ in IRIS. Therefore, if the IRIS is performed for interpretation of non-relevant indication and measurement of wall-loss rate after ECT, reliability is supposed to be improved.

Development of Real-time and Simultaneous Quantification of Volatile Organic Compounds in Ambient with SIFT-MS (Selected Ion Flow Tube-Mass Spectrometry) (선택적다중이온질량분석기를 이용한 대기 중 휘발성유기화합물 실시간 동시분석법 개발 및 적용)

  • Son, Hyun Dong;An, Joon Geon;Ha, Sung Yong;Kim, Gi Beum;Yim, Un Hyuk
    • Journal of Korean Society for Atmospheric Environment
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    • v.34 no.3
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    • pp.393-405
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    • 2018
  • Volatile organic compounds (VOCs) are representative air pollutants due to their detrimental effects on human health and their role in formation of secondary organic aerosols. Assessments and monitoring programs of VOCs using periodic grab sampling like Tedlar bags, canisters, and sorbent traps provide limited information, often with delay times of days or weeks. Selected ion flow tube mass spectrometry (SIFT-MS) is an emerging analytical technique for the real-time quantification of VOCs in air. It relies on chemical ionization of the VOCs molecules in air introduced into helium carrier gas using $H_3O^+$, $NO^+$, and $O_2{^+}$ precursor ions. Real-time monitoring method of 60 VOCs in the ambient air was developed using TO-15 standard gas mixture. Calibration curves, method detection limit, and quantitation reproducibility of the target compounds were tested. Dynamic dilution system was used to dilute standard gas from 0.174 ppbv to 100 ppbv, where calibration curves showed good linearity with $r^2$> 0.95 in all target analytes. Limit of detection (LOD) all compounds were sub ppbv, and some halogenated compounds showed pptv levels. Seven consecutive analyses of target compounds showed good repeatability with relative standard deviation of less than 10%. One day monitoring of VOCs in ambient air was conducted in Geoje. Average concentration of target VOCs in Geoje were relatively lower than other regions, among which formaldehyde showed the highest concentration ($15.4{\pm}5.78ppbv$). SIFT-MS provided good temporal resolution data (1 data per 3.2 minute), which can be used for identifying ephemeral short-term event. It is expected that SIFT-MS will be a versatile monitoring platform for VOCs in ambient air.