BED-DETECTING METHOD FOR DETECTING AREA AND STATE OF FLOW OF UNDERGROUND WATER

摘要

PURPOSE:To perform detection accurately and simply in a short time by a method wherein a water-intercepting hollow insulation pipe serving as a guide pipe for moving a sonde vertically is inserted into a well to separate water in the well completely from the inside of the pipe and measurement is conducted in the state wherein the turbulence of the water in the well is prevented completely. CONSTITUTION:On the outer surface of an insulation electrode pipe 5 made of polyvinyl chloride or the like and separating water in a well completely from the inside of the pipe, a number of electrodes in the shape of a screw or the like are arranged at symmetrical positions on the circumference and in the longitudinal direction at appropriate intervals for measurement. A contact measurement rod 9 is inserted into the insulation electrode pipe 5 and lowered down to the bottom of the pipe. Then, while a specified constant current is made to flow between current electrodes A and B from a measuring unit, the rod is pulled up sequentially and a potential generated at each position of the electrodes is measured as a potential difference between the potential M and the electrode N. By this method, the turbulence of the water in the well can be prevented completely, and thus the detection can be performed accurately and simply in a short time.