Signal Loss, Spatial Resolution, and Sensitivity of Long Coaxial Crack Sensors
Configuration-based coaxial cable sensors have recently been developed to detect cracks in reinforced concrete (RC) structures. These sensors have shown a high sensitivity when applied to several short RC flexural members. However, the signal losses resulting from a long cable sensor may distort the initial waveform of the electromagnetic wave propagating along the cable, thereby compromising the spatial resolution and sensitivity of this sensor. The signal losses consist of the contributions from the skin effect of conductors, energy absorption in the dielectric material, and impedance mismatch loss due to multiple signal reflections resulting from discontinuities caused by the separation between the adjacent spirals, which acts as the outer conductor of a cable sensor. This paper summarizes the basic physics of signal losses in cable sensors, and investigates the impact of the signal losses on the spatial resolution and sensitivity of a cable sensor over distance. Several methods are proposed to simulate and quantify various factors affecting the signal losses.
S. Sun et al., "Signal Loss, Spatial Resolution, and Sensitivity of Long Coaxial Crack Sensors," Proceedings Volume 5391, Smart Structures and Materials 2004: Sensors and Smart Structures Technologies for Civil, Mechanical, and Aerospace Systems, SPIE -- The International Society for Optical Engineering, Jul 2004.
The definitive version is available at http://dx.doi.org/10.1117/12.540033
Smart Structures and Materials (2004: Mar. 14-18, San Diego, CA)
Civil, Architectural and Environmental Engineering
Electrical and Computer Engineering
Materials Science and Engineering
Keywords and Phrases
Coaxial Cable Sensors; Reinforced Concrete (RC) Structures; Signal Loss
Article - Conference proceedings
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