• International Journal of Safety
• /
• v.7 no.2
• /
• pp.1-6
• /
• 2008

In this paper, the effects of the position and the angle of the potential probes on the measurements of the ground resistance using the fall-of-potential method are described and the testing techniques for minimizing the measuring errors are proposed. The fall-of-potential method is theoretically based on the potential and current measuring principle and the measuring error is primarily caused by the position and angle of auxiliary probes. In order to analyze the relative error in the measured value of the ground resistance due to the position of the potential probe, the ground resistance was measured for the case in which the distance of the current probe was fixed at 50[m] and the distance of the potential probe was located from 10[m] to 50[m]. Also, the potential probe was located in turn at $30[^{\circ}]$, $45[^{\circ}]$, $60[^{\circ}]$, $90[^{\circ}]$, and $180[^{\circ}]$. As a consequence, relative error decreased with increasing distance of the potential probe and decreasing angle between the current probe and potential probe. The results could help to determine the position of the potential probe during the ground resistance measurement.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.23 no.2
• /
• pp.96-102
• /
• 2009

In this paper, the effects of the position and the angle of the potential probes on the measurements of the ground resistance with the fall-of-potential method are described and the testing techniques to minimize the measuring errors are proposed. The fall-of-potential method is theoretically based on the potential and current measuring principle and the measuring error is primarily caused by the position and angle of auxiliary probes. In order to analyze the relative error for measuring value of ground resistance due to the position of the potential probe, ground resistance were measured in case that the distance of current probe was fixed at 50[m] and the distance of potential probe was located from l0[m] to 50[m]. Also, the potential probe was located at 30[$^{\circ}$], 45[$^{\circ}$], 60[$^{\circ}$], 90[$^{\circ}$] and 180[$^{\circ}$]. As a consequence, relative error decreased with increasing the distance of potential probe and decreasing the angle between current probe and potential probe. The results could be help to determine the position of potential probe when the ground resistance was measured at grounding system.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2010.02a
• /
• pp.465-465
• /
• 2010

Cut off probe, the efficient method, can measure the plasma parameters like the plasma electron density and the electron temperature. Plasma potential is also one of the important parameters in plasma processing but cannot be measured by cut off probe yet. Thus we developed method to measure plasma potential by focusing on relation between bias on a tip and sheath around tip. The system consist of a ICP(Inductive Coupled Plasma) source, a Network analyzer and a bias tee that can be bridge apply DC voltage on the cut off probe tip. Plasma potential is identified by using this system. The results corresponded well with the measured results by single langmuir probe(SLP).

• Journal of the Korean Society of Safety
• /
• v.27 no.4
• /
• pp.33-37
• /
• 2012

This paper describes the characteristics for ground impedance of counterpoise according to position of auxiliary probe and frequency using the fall-of-potential method and the testing techniques to minimize the measuring errors are proposed. The fall-of-potential method is theoretically based on the potential and current measuring principle and the measuring error is primarily caused by the position of auxiliary probes. In order to analyze the effects of ground impedance due to the distance of the current probe and frequency, ground impedances were measured in case that the distance of current probe was located from 10[m] to 100[m] and the measuring frequency was ranged in 55 [Hz], 128[Hz], 342[Hz], and 513[Hz]. The results could be help to determine the position of auxiliary probe when the ground impedance was measured at grounding system.

• Journal of the Korean Society of Safety
• /
• v.30 no.4
• /
• pp.46-50
• /
• 2015

This paper describes the measurement and analysis of ground impedance according to arrangement of auxiliary probe around ground grid using the fall-of-potential method and the testing techniques to minimize the measuring errors are proposed. The fall-of-potential method involves passing a current between a ground electrode and a current probe, and then measuring the voltage between a ground electrode and a potential probe. To minimize interelectrode influences due to mutual resistances, the current probe is a generally placed at a substantial distance from the ground electrode under test. In order to analyze the effects of ground impedance due to the arrangement of auxiliary probe and frequency, ground impedances were measured in case that the arrangements of auxiliary probe were straight line, perpendicular line, and horizontal line. The distance of current probe was located from 10[m] to 200[m] and the measuring frequency was ranged from 55[Hz] to 513[Hz]. As a consequence, the ground impedance increases with increasing the distance from the ground electrode to the point to be tested, but the ground impedance decreases with increasing the frequency.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2008.10a
• /
• pp.367-370
• /
• 2008

In this paper, the effects of the position and the angle of the auxiliary probes on the measurements of the low frequency ground impedance with the fall-of-potential method are described iud the testing techniques to minimize the measuring errors are proposed. The fall-of-pot ential method is theoretically based on the potential and current measuring principle and the measuring error is primarily caused by the position and angle of auxiliary probes. In order to analyze the characteristics of ground impedance due to the location of the potential probe, ground impedances were measured in case that the distance of current probe was fixed at 50[m] and the distance of potential probe was located from 10[m] to 50[m]. Also, the potential robe was located at 30[$^{\circ}$], 40[$^{\circ}$], 60[$^{\circ}$], 90[$^{\circ}$], and 180[$^{\circ}$]. The results could be help to determine the location of potential probe when the ground impedance was measured at grounding system.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2009.05a
• /
• pp.289-292
• /
• 2009

This paper describes the analysis for ground impedance measurement influenced by distance of current probe and frequency using the fall-of-potential method and the testing techniques to minimize the measuring errors are proposed. The fall-of-potential method is theoretically based on the potential and current measuring principle and the measuring error is primarily caused by the position of auxiliary probes. In order to analyze the effects of ground impedance due to the distance of the current probe and frequency, ground impedances were measured in case that the distance of current probe was located from 5[m] to 20[m] and the measuring frequency was ranged in 55[Hz], 128[Hz], 342[Hz], and 513[Hz]. The results could be help to determine the position of current probe when the ground impedance was measured at grounding system.

• Applied Microscopy
• /
• v.44 no.3
• /
• pp.100-104
• /
• 2014

As decreasing device size, probing of nanoscale surface properties becomes more significant. In particular, nanoscale probing of surface potential has paid much attention for understanding various surface phenomena. In this article, we review different atomic force microscopy techniques, including electrostatic force microscopy and Kelvin probe force microscopy, for measuring surface potential at the nanoscale. The review could provide fundamental information on the probing method of surface potential using atomic force microscopy.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.24 no.4 s.175
• /
• pp.874-880
• /
• 2000

In this paper, a DC potential drop measurement system was used to find the position of the flaw on a simple thin plate. Four-point probe test was evaluated and used for this study. In the four-point probe test, the more distance between current pins provides the more measurable scope, the less voltage difference, and the more voltage difference rate. In the other hand, the more distance between voltage pins provides the less voltage difference and the less voltage difference rate. An optimized four-point probe was applied to measure the relation between voltage and the relative position of flaw to the probe. The Maxwell 21) simulator was used to analyze the electromagnetic field, and it showed that the analytical result was similar to the experimental result within 11.4% maximum error.

• Tribology and Lubricants
• /
• v.11 no.5
• /
• pp.40-46
• /
• 1995

This study concerns the design and development of the non-vibrating capacitance probe which could be used as a non-contact sensor for tribological wear. This device detects surface charge through temporal variation in the work function of a material. Experiments are performed to demonstrate the operation of the probe on a roating aluminum shaft. The reference electrode of the probe, made of lead, is placed adjacent (< 1.25-mm distance) to the shaft. Both surfaces which are electrically connected, form a capacitor. An artificial spatial variation in the work function is imposed on the shaft surface by coating a segment along the shaft circumference with a colloidal silver paint. As the shaft rotates, the reference electode senses changing contact potential difference with the shaft surface, owing to compositional variation. Temporal variation in the contact potential difference induces a current through the electrical connection. This current is amplified and converted to a voltage signal by an electoronic circuit with an operational amplifier. The magnitude of the signal decreases asymptotically with the electrode-shaft distance and increases linearly with the rotational frequency. These results are consistent with the theoretical model. Potential applications of the probe on wear monitoring are proposed.