Abstract
We investigated the performance of instruments to determine the working resistance of the real-time soil sensor. The working resistance was estimated from the moment acting on the shank with a chisel implement, and the vertical and horizontal components of force acting on the chisel tip to cut the soil. Two measuring devices with a one-way-detecting compression transducer and a cantilever-shaped round-detecting load transducer were developed to monitor the forces on the chisel tip. The one-way-detecting compression transducer detected hysteresis in the loading and unloading due to friction effects induced by vertical force. The cantilever type showed a correlation coefficient of 0.997 with the horizontal force and 0.994 with the vertical force in situ. A field experiment yielded a correlation coefficient of 0.661 between the horizontal load measured by the cantilever type and the resistance of the cone penetrometer.
