Patent ID: 8030946

Claim:
A system for inspecting an internal, non conductive coating along a length of pipe, the system including a pipe inspection device, the pipe inspection device comprising: a thickness sensor for determining measurements of a thickness of the internal coating along the length of pipe defining thickness measurements, the thickness sensor comprising one or more probes each having a support mechanism which provides substantially constant contact with a surface of the internal coating so that values of the thickness measurements are responsive to changes in the thickness of the internal coating; and a holiday detector for detecting holidays within the internal coating along the length of pipe, the holiday detector configured to trigger when holidays are present within the internal coating at a given location under evaluation along the internal coating and further configured to employ an adjustable voltage adjusted to maintain the voltage applied at the given location to between a value at or above a breakdown voltage of environmental fluid in presence of a holiday at the given location when so existing and less than a breakdown voltage of the internal coating for a measured thickness at the given location in absence of a holiday responsive to the measurements of the changes in the thickness of the internal coating along the length of pipe.