The paper recommends that the placement of voltage - electrode is 0 . 509s when the distance from the border of grounding grids to current - electrode is s that is the long border length of grids . ( 3 ) the paper use two - layer theory to describe non - uniform soil . with the different two - layer soil model , some conclusions and formula that have great reference value are presented numerically 綜合各種因素考慮,推薦在距離地網(wǎng)邊緣距離為地網(wǎng)長(zhǎng)邊長(zhǎng)度s的位置布置電流極,并在0 . 509s布置電壓測(cè)量極,在滿足工程精度要求的同時(shí)也極大的提高了測(cè)量效率。