Utilization of Magnetic Viscosity Effects in Soils for Archaeological Prospection

• DOI: 10.1038/2121446a0
• Publication Date: 2006-07-06T03:10:55Z
• Authors: C. COLANI; M. J. AITKEN
• Keywords: Prospection; Square (algebra)

DURING the evaluation of a new type of metal detector on various archaeological sites in England during the past summer, it has been observed that the instrument is also sensitive to non-metallic features such as filled-in pits and buried hearths. Instead of a conventional system of continuous sinusoidal currents (and associated magnetic fields), this instrument uses repeated rectangular unipolar pulses; these are fed to a transmitter coil (which in the present instance is square, of side length 1.2 m, and 6 turns) laid flat on the ground. The voltage induced in a receiver coil concentric with the transmitter coil is fed to a fast-recovery d.c. amplifier.