ID-OD discrimination sensor

An instrument pig for analyzing anomalies in a wall of a pipeline, the pig comprising:

• a tow portion for moving the pig through the pipeline;
• an instrument portion for measuring the anomalies in the pipeline wall comprising:
• a plurality of arms disposed circumferentially around the instrument portion, each arm flexibly mounted on the instrument portion to allow the arm to move radially inwardly and radially outwardly to provide clearance for the pig in the event that it encounters obstructions as it travels through the pipeline;
• a sensor body mounted to each arm and comprising a circuit board, a single coil wrapped around the circuit board and a microcontroller mounted to the circuit board and connected with the single coil for inducing a waveform on the coil to thereby create an eddy current in the pipeline wall adjacent the sensor body, and the microcontroller measuring changes in a characteristic of the induced waveform on the single coil that correspond to the presence of anomalies on an inside diameter of the pipeline wall, and the sensor body comprising a sensor body cover molded about the circuit board, the microcontroller and the single coil, the sensor body cover consisting essentially of a wear resistant, non-conductive material including a polymer material, and
• magnets mounted on the arms for generating and transmitting a magnetic field through portions of the pipeline wall adjacent the sensor body;
• and,
• a data storage portion for storing data measured by the microcontroller.