METHOD AND APPARATUS FOR MEASURING EMBEDDED DEPTH OF EMBEDDED LONG BODY

摘要

PURPOSE:To measure the embedded depth of an embedded long body only from a magnetic field magnetized by a geomagnetic field, by allowing a sensor conveyor having a magnetic sensor mounted thereto to run on a surface to be investigated while further moving the magnetic sensor independently at a high speed. CONSTITUTION:An embedded depth measuring apparatus 1 is towed by a research vessel 5 to be allowed to run on the seabottom surface 2 while each sensor reciprocal moving mechanism 11 is driven by a speed controller and sensor coils 81-84 are reciprocally moved on a sensor conveyor 6. When only a parallel magnetic field such as a geomagnetic field is present, no electromotive voltage is generated in the sensors 8 but, in the vicinity of an embedded long body 3 which is magnetized by the geomagnetic field and generates a weak magnetic field in a vortex form, an AC wave form coming to one cycle in reciprocation is generated. By selecting and amplifying this AC wave form signal by the control and data proessing part 10 on the vessel, the embedded depth of the embedded long body 3 is measured.