四探针法测量土壤电阻率的探讨

文章对四探针法测量土壤电阻率的原理进行了研究.假设大地表面层土壤全为同一电阻率为ρ的均匀介质,当接地器中有恒定电流流过时,在土壤中建立了恒定电场,恒定电场满足拉普拉斯方程,依据球坐标系下的拉普拉斯方程,得到了土壤中任意一点的电位的解.在四探针严格地位于一条直线的方法,并分析了与土壤电阻率有关的因素,为电力系统的接地技术提供了重要参考依据.

Research on Soil Resistivity with Four- probe Method

The principle with four -probe method survey soil resistivity has been summarized in the arti-cle. The earth surface layer soil as the even medium and the identical resistivity is supposed. When the constantcurrent flows in the earthing electrode, the steady electric field is esablished in the soil. The steady electric fieldsatisfies Laplace equation. According to the Laplace equation in the spherical coordinates, the electric potentialsolution at any point in the field can be obtained. We derived the soil resistivity's formula for the four - probestrict in a straight line and equidistance. In order to reduce the measurement error, it is best to survey severaltimes at the different direction, and we take its mean value. We analyzed the various related factors with the soilresistivity, and provided the important reference for the earthing technique.