TY - GEN
T1 - DC potential drop technique selecting probes distances properly for sizing deep surface cracks
AU - Takeo, Fumio
AU - Saka, Masumi
AU - Hamada, Seiichi
AU - Hayakawa, Manabu
N1 - Copyright:
Copyright 2013 Elsevier B.V., All rights reserved.
PY - 2005
Y1 - 2005
N2 - D-C potential drop (DCPD) technique is a powerful tool for quantitative NDE of cracks. The technique using four probes which are in close proximity to each other has been proposed for NDE of surface cracks; that is the closely coupled probes potential drop (CCPPD) technique. It has been shown that the sensitivity of CCPPD technique to evaluate a small crack is enhanced significantly in comparison with the usual method. On the other hand, since CCPPD technique has been developed to evaluate a small crack sensitively, it is not fit to evaluate deep cracks which are sometimes found in the structural components of power plants. The objective of this study was to enhance the sensitivity of evaluating deep surface cracks. By extending the distance between current input and output probes, the change in potential drop with the change in the depth of deeper crack becomes large. But the voltage of potential drop becomes small to measure, because the current density in the material becomes low. The voltage of the potential drop can be increased by increasing the applying current, but the current would also be limited by the equipment or contacting probes. Then the way to select the appropriate distances between probes from the viewpoints of the sensitivity and the required current has been shown.
AB - D-C potential drop (DCPD) technique is a powerful tool for quantitative NDE of cracks. The technique using four probes which are in close proximity to each other has been proposed for NDE of surface cracks; that is the closely coupled probes potential drop (CCPPD) technique. It has been shown that the sensitivity of CCPPD technique to evaluate a small crack is enhanced significantly in comparison with the usual method. On the other hand, since CCPPD technique has been developed to evaluate a small crack sensitively, it is not fit to evaluate deep cracks which are sometimes found in the structural components of power plants. The objective of this study was to enhance the sensitivity of evaluating deep surface cracks. By extending the distance between current input and output probes, the change in potential drop with the change in the depth of deeper crack becomes large. But the voltage of potential drop becomes small to measure, because the current density in the material becomes low. The voltage of the potential drop can be increased by increasing the applying current, but the current would also be limited by the equipment or contacting probes. Then the way to select the appropriate distances between probes from the viewpoints of the sensitivity and the required current has been shown.
KW - D-C Potential Drop Technique
KW - Deep Crack
KW - Non-Destructive Evaluation
KW - Probes Distances
UR - http://www.scopus.com/inward/record.url?scp=33645665262&partnerID=8YFLogxK
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U2 - 10.1115/IMECE2005-79877
DO - 10.1115/IMECE2005-79877
M3 - Conference contribution
AN - SCOPUS:33645665262
SN - 0791842266
SN - 9780791842263
T3 - American Society of Mechanical Engineers, Nondestructive Evaluation Engineering Division (Publication) NDE
SP - 47
EP - 52
BT - Proceedings of the ASME Nondestructive Evaluation Engineering Division 2005
T2 - 2005 ASME International Mechanical Engineering Congress and Exposition, IMECE 2005
Y2 - 5 November 2005 through 11 November 2005
ER -