• Title, Summary, Keyword: Pole electrode method

Search Result 14, Processing Time 0.038 seconds

Analysis of Electrical Resistivity Characteristics of Concrete by Using Flat Electrode Method (평판접지 전극방법을 이용한 콘크리트의 전기비저항 특성 분석)

  • Park, Chang Seon;Park, Hae Won;Lee, Kang Hun;Jeong, Jin Hoon
    • International Journal of Highway Engineering
    • /
    • v.19 no.3
    • /
    • pp.57-63
    • /
    • 2017
  • PURPOSES : The pole electrode method damaged the concrete pavement on inserting the electrode into the pavement surface. This study examined the feasibility of the flat electrode method to observe the concrete pavement instead of the pole electrode method and analyzed the resistivity characteristics of the concrete by performing laboratory tests. METHODS : The resistivity of the concrete specimens manufactured with three different mixing ratios (38.50%, 39.50%, and 40.50%) were measured using the pole and flat electrode methods according to the concrete age (7 and 28 days) and electrode spacing (20 mm, 30 mm, and 40 mm). RESULTS :In both pole and flat electrode methods, the resistivity increased with increasing fine aggregate proportion regardless of the concrete age. The resistivity measured at a concrete age of 28 days was slightly larger than that measured at 7 days. In the case of a concrete age of 7 days, the resistivity measured by the flat electrode method was larger than that measured by the pole electrode method. The difference disappeared at 28 days. CONCLUSIONS :The results suggest that the flat electrode method can replace the pole electrode method because the resistivity measured by both methods was similar. Hence, the development of a technology to apply the flat electrode method to actual concrete pavement is necessary.

The Comparison and Analysis about Earth Resistance for Measuring of Earth Resistance by Measurement Positions of Auxiliary Poles (접지저항 측정을 위한 보조전극 위치에 따른 접지저항 비교 분석)

  • Han, Woon-Ki;Jung, Jin-Soo;Kim, Jae-Chul
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
    • /
    • v.23 no.10
    • /
    • pp.128-133
    • /
    • 2009
  • This paper describes the comparison and analysis about measurement method of earthing resistance by positions of potential pole and current pole. In KOREA, a diagonal by 6.5 times of earthing electrode for measurement of earthing resistances but this method was almost impossible in the downtown area. For solving this problem, in this paper measuring of earthing resistance changing parameters. The parameter was a distances of earthing electrode, potential pole & current pole and the another parameter was an angles of potential pole & current pole. Analysis result, earthing resistance stability that conditions. Fist, distance from earthing electrode to current pole was over 50[m] and distance from earthing electrode to potential pole was over 30[m]. Second, angles of potential pole & current pole was over $45[^{\circ}]$.

The Effect of Process Parameter on the Symmetry of Nugget in Micro-resistance Series Spot Welding (정밀저항시리즈 점용접에서 너깃의 대칭성에 미치는 공정변수의 영향)

  • 조상명;김송미
    • Journal of Welding and Joining
    • /
    • v.19 no.6
    • /
    • pp.622-629
    • /
    • 2001
  • The aim of this experiment is to establish the method that obtains symmetrically two nuggets in microresistance series spot welding. The sheets of austenite stainless steel STS304 applied to various electronic parts were experimented by the inverter welding power source of polarity controllable type and by the twin head for left and right electrode force to be controlled separately. The experimental results were obtained as follows : 1) When series spot welding was carried out by DC 1 pulse as welding current with same electrode force at left and right, the asymmetry of nuggets was resulted from the larger nugget of the (-) pole because of the Peltier effect. The dynamic resistance of weld spot at left and right was appeared differently according to the growth of nuggets. 2) When AC 1 cycle by welding power source of polarity controllable type was applied, the nuggets were almost symmetrically formed. 3) In a twin head, if the electrode force of (-) pole was larger than that of (+) pole, the diameters of two nuggets became to same. It was confirmed that the dynamic resistance of (-) pole was decreased to the same level as it of (+) pole. 4) Although the forces of left and right electrode were same, and only DC 1 pulse was applied, symmetric nuggets were obtained if the conductivity of (+) pole was lower than it of (-) pole.

  • PDF

The Crosshole Resistivity Method Using the Mixed Array (혼합배열을 사용하는 시추공간 전기비저항 탐사)

  • Cho In-Ky;Han Sung-Hoon;Kim Ki-Ju
    • Geophysics and Geophysical Exploration
    • /
    • v.5 no.4
    • /
    • pp.250-256
    • /
    • 2002
  • Resistivity tomography has become an important tool to image underground resistivity distribution. This method has been widely applied to site investigation for engineering and environmental purpose. In resistivity tomography, various electrode arrays can be used and each array has both merits and demerits. For example, the pole-pole array has high signal to noise ratio (S/N ratio), but its resolution is too low. The dipole-dipole array has low S/N ratio, but its resolution is very high. The Pole-dipole may has intermediate Snf ratio and resolution. The modified Pole-dipole array, recently proposed, shows reasonable S/N ratio and resolution, which are comparable to the pole-dipole array. These electrode arrays except the pole-pole array, however, have the problem that the apparent resistivity can diverge at some special electrode Positions. Also, the Pole-Pole array may not reflect the doe resistivity of an anomalous body. In this study, we propose a new electrode array, mixed array, where pole-dipole and modified pole-dipole ways are selectively used with the relative positions of current and potential electrodes. The mixed array has the same level of S/N ratio and resolution as the pole-dipole array and the apparent resistivity does not diverge in the receiver hole. Furthermore, the apparent resistivity using the array can reflect the true resistivity of the anomalous body.

Fabrication of MEMS Inkjet Head for Drop-on-Demand Ejection of Electrostatic Force Method (정전기력 방식의 Drop-on-Demand 토출을 위한 MEMS 잉크젯헤드 제작)

  • Son, S.U.;Kim, Y.M.;Choi, J.Y.;Ko, H.S.;Kim, Y.J.;Byun, D.Y.;Lee, S.H.
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.56 no.8
    • /
    • pp.1441-1444
    • /
    • 2007
  • This paper presents a novel electrostatic drop-an-demand ejector with a conductive pole inside nozzle. The MEMS fabricated pole-type nozzle shows a significant improvement in the performance and reliability of forming meniscus and generating a micro dripping mode of droplet out of the meniscus. It is verified experimentally that the use of the pole-type nozzle. The liquid is used D20+SDS+SWNT (5 %wt). The gap between upper electrode and nozzle is about 600 um. Electrostatic drop-an-demand ejection is observed when a DC voltage of 1.5 kV is applied between the control electrode and ground electrode. Droplet diameter is $100{\mu}m$.

Scaled Model Study on the Underground Mise-à-la-masse Method (갱도(坑道)를 이용(利用)한 인공분극법(人工分極法) 모형(模型) 연구(硏究))

  • Suh, Baek-Soo;Song, Young-Soo
    • Journal of Industrial Technology
    • /
    • v.5
    • /
    • pp.81-89
    • /
    • 1985
  • A Mise-$\grave{a}$-la-masse method is to use a subsurface conductive mass itself as one current electrode of a pair by connecting it directly to one pole of a voltage source, the second current electrode being placed on the ground surface at a great distance and connected to the other pole. This paper is to study the modified Mise-$\grave{a}$-la-masse method using a water tank, that is, the second current electrode is placed on the underground level instead of being placed at a great distance, to find the geometry and the continuity of ore bodies.

  • PDF

Micro End-milling Technology for Micro Pole Structures (미세 폴 구조물 가공을 위한 마이크로 앤드밀링 기술)

  • Je, Tae-Jin;Choi, Doo-Sun;Lee, Eung-Sug;Hong, Sung-Min;Lee, Jong-Chan;Choi, Han
    • Journal of the Korean Society of Manufacturing Process Engineers
    • /
    • v.4 no.4
    • /
    • pp.7-13
    • /
    • 2005
  • In the case of fabricating micro pole structures such as column, square-pole and gear shaft by the micro end-milling process, it can be useful in the fields of industry, for example, micro parts, electrode for electrical discharge machining and micro mold for injection molding. In this study, machining factors and the process were analyzed. Machining experiments of various micro pole configurations were performed. Analysis of the change and effect of the cutting force according to the machining conditions was carried out. An analytical study of the deformation of the micro pole caused cutting conditions and cutting force through the finite element method and ANSYS program was carried out. As a result, this research presented a method of fabricating the column pole of below $100{\mu}m$ diameter with high aspect ratio by using micro end-milling process, and based on that, a method of fabricating a variety of applicable structures. Also the minimum size of the pole capable of fabricating through theory and experiment were demonstrated.

  • PDF

Theoretical and experimental studies on influence of electrode variations in electrical resistivity survey for tunnel ahead prediction (터널 굴착면 전방조사를 위한 전기비저항 탐사에서 전극의 변화가 미치는 영향에 대한 이론 및 실험연구)

  • Hong, Chang-Ho;Chong, Song-Hun;Hong, Eun-Soo;Cho, Gye-Chun;Kwon, Tae-Hyuk
    • Journal of Korean Tunnelling and Underground Space Association
    • /
    • v.21 no.2
    • /
    • pp.267-278
    • /
    • 2019
  • Variety of tunnel ahead prediction methods have been performed for safe tunnel construction during tunnel excavation. Pole-pole array among the electrical resistivity survey, which is one of the tunnel ahead prediction method, has been utilized to predict water-bearing sediments or weak zone located within 5 times of tunnel diameter. One of the most important processes is the estimation of virgin ground resistivity and it can be obtained from the following process: 1) calculation of contact area between the electrodes and the medium, and 2) assumption of the electrodes as equivalent spherical electrodes which have a same surface area with the electrodes. This assumption is valid in a small contact area and sufficient distance between the electrodes. Since the measured resistance, in general, varies with the electrode size, shape, and distance between the electrodes, it is necessary to evaluate the influence of these factors. In this study, theoretical equations were derived and experimental tests were conducted considering the electrode size, shape, and distance of cylindrical electrodes which is the most commonly utilized electrode shape. Through this theoretical and experimental study, it is known that one should be careful to use the assumption of the equivalent half-spherical electrode with large ratio between the penetrated depth and radius of the cylindrical electrode, as the error may get larger.

Application of SP and Pole-pole Array Electrical Resistivity Surveys to the Seawater Leakage Problem of the Embankment (방조제 누수지점 탐지를 위한 SP및 단극배열 전기비저항탐사의 적용)

  • 송성호;이규상;김진호;권병두
    • Economic and Environmental Geology
    • /
    • v.33 no.5
    • /
    • pp.417-424
    • /
    • 2000
  • We applied SP monitoring and resistivity surveys using the pole-pole electrode array to seawater leakage problems in the Youngsan estuary dam and the Eoeun embankment to estimate and detect the zone of seawater leakage. The embankment is generally affected by tidal variation and has low resistivity characteristics due to the high saturation of seawater. For this reason, SP monitoring and the pole-pole array resistivity surveys, which are relatively more effective to the conductive media, were carried out to delineate the leakage zones of sea water through the embankment. We checked out electrical conductivity (EC) and temperature variations along the inner part of Youngsan estuary dam to detect the zone of seawater leakage and found that the measured EC value agreed to that of seawater in the leakage zone and the temperature was lower than that of the vicinity of leakage zone. SP monitoring results were coincided with tidal variations at each embankment. At the leakage zones in the Youngsan estuary dam and the Eoeun embankment, SP anomalies are in the range of -60~-85 mV and -20~-50 mV, respectively, and true resistivity values obtained by 2-D inversion are 3~15 ohm-m and below 0.3 ohm-m, respectively. Both SP monitoring and the pole-pole array resistivity method are found to be quite effective for investigation of seawater leakage zones in the embankment.

  • PDF

Application of resistivity monitoring to examine the grouting effect

  • Farooq, Muhammad;Park, Sam-Gyu;Kim, Jung-Ho;Song, Young-Soo
    • 한국지구물리탐사학회:학술대회논문집
    • /
    • /
    • pp.79-82
    • /
    • 2006
  • This paper presents to examine the ability of an electrical resistivity method to monitor the grouting effect at subsidence area. To monitor the changes in ground resistivity before and during the grout, series of electrical resistivity monitoring surveys have been conducted. Data has acquired in the form of grid making nine lines parallel to road and four lines traverse the road. Two kinds of electrode arrays modify pole-pole and dipole-dipole arrays were used during resistivity data acquisition. In this paper, the results show that electrical prospecting is an effective method to detect low resistivity imaging zone by grout during the ground reinforcement.

  • PDF