抵抗傾度測定に依る新しき電氣探鑛法に就て

抄録

The effect of the electrode spacing and the physical conditions (size, shape, position, etc.) of the conductor on the “kick” of the curve in the apparent resistivity methodof electrical prospecting has already been discussed in a previous paper by the author.
The position of the unknown conductor is determined by the “kicks” on the curve.However, in the ordinary resistivity methods the curves are affected greatly by therelative position of the ground surface to the physical conditions of the conductor, sothat at times the kick of the curve vanishes completely making interpretations impossible.Apparent resistivity curves always have a positive value, so that, even thoughlarge resistivity variations may occur in the underground medium, the resistivity readingstend to only change gradually.
Intending to improve upoil these shortcomings of the ordinary resistivity method, the author has experimented and theoretically discussed the possibility of differentiatingthe ordinary resistivity curve. The result of his work being the announcement ofthis new method.
The electrode system is similar to the well known Wenner arrangement, however, a fifth electrode is placed at either infinity or in the middle of the electrode system.The apparent resistivity gradient formulas for this new system are Δρ=4παΔR, andΔρ=3παΔR, respe6tively for the two arrangements.
The measuring apparatus and the operation of this new method are almost identicalwith the ordinary Megger method, however, the shape of the curve, from which theposition and dimensions of the conductor is determined, is a great improvement overthe ordinary resistivity method.