Pipe inspection cable counter and overlay management system

A pipe inspection system, comprising:

• a frame;
• a hollow cable storage drum;
• an axle supported by the frame and supporting the cable storage drum for rotation about the axle;
• a resilient flexible push-cable stored in turns inside the cable storage drum and having a distal end and a proximal end;
• a camera head connected to the proximal end of the push cable;
• a pair of permanent magnets mounted on the cable storage drum for rotation therewith;
• and
• a magnetic sensor mounted in a fixed position on the frame adjacent the axle so that the permanent magnets rotate the same, the magnetic sensor being capable of generating signals representing changes in a composite magnetic field in at least two axes as the permanent magnets rotate around the magnetic sensor.

A pipe inspection system, comprising:

• a frame;
• a hollow cable storage drum;
• an axle supported by the frame and supporting the cable storage drum for rotation about the axle;
• a resilient flexible push-cable stored in turns inside the cable storage drum and having a distal end and a proximal end;
• a camera head connected to the proximal end of the push cable;
• a pair of cylindrical Neodymium magnets mounted on the cable storage drum for rotation
• therewith, the permanent magnets being mounted so that their magnetic axes are aligned and pass substantially through an axis of rotation of the cable storage drum, the North pole of one of the magnets opposing the South pole of the other one of the magnets;
• a magnetic sensor including a plurality of Hall effect devices mounted in a fixed position on the frame adjacent the axle so that the permanent magnets rotate the same, the magnetic sensor being capable of generating signals representing changes in a composite magnetic field in at least two axes as the permanent magnets rotate around the magnetic sensor;
• and
• wherein a first distance between the permanent magnets is greater than about one and one half times a second radial offset distance from a center of the magnetic sensor to the axis of rotation of the cable storage drum.