Patent ID: 7421910
Filing Date: 2008-09-09
Classification: G01M

Abstract:
1. A coax cable sensor for use in a electrical time domain transmission or electrical time domain reflectometry system to detect and measure strain in an associated structure, the sensor comprising: an inner conductor defining a sensing length to correspond to the associated structure or a portion of the associated structure to be monitored and configured on one end to couple to a sensor head; a dielectric jacket disposed around said inner conductor and configured to electrically insulate an outer conductor over the sensing length; said outer conductor electrically insulated by the dielectric jacket from said inner conductor along the sensing length and being configured on one end to couple to the sensor head; deformation means associated with the outer conductor for creating localized deformation that creates an electrically detectable inductance change with respect to said outer conductor in response to strain applied to the coax cable sensor by the associated structure; wherein said deformation means comprises periodic points of discontinuity in said outer conductor; and wherein said outer conductor comprises an electrically conductive wrap and points of discontinuity are defined by adjacent turns of said electrically conductive wrap.