An electromagnetic sensor to locate service laterals during the trenchless lateral reinstatement

Lateral reinstatement is the last step in the rehabilitation of buried pipes using cured-in-place pipe (CIPP) liners, where the service laterals sealed by the freshly installed liner are cut open. In this paper, a low cost sensor based on the open-ended rectangular waveguide based non-destructive testing (NDT) technique that was developed in the past is extended for lateral detection. Its performance is tested inside metallic and non-metallic host pipes. Numerical modeling of the sensor and experimental validations are carried out. A dedicated electronic circuit and a servo controlled scanning mechanism are developed so that the sensor can be retrofitted on the robotic cutters used for lateral restoration in the trenchless industry.