A technique for horizontal measurement of soil mechanical impedance.

ABSTRACT Two prototype horizontal operating soil penetrometers, a prismatic tip and a cone tip, were developed and compared to a vertically operated standard Delmi penetrometer. A sandy soil and a clay soil at two moisture contents and two penetration rates, 3 and 9 cm/s, were employed to evaluate the penetrometers in a laboratory soil bin. Experimental tests were arranged in a randomized complete block design with six replications. Both penetrometer tips performed satisfactorily and could serve as a basis for on-the-go penetration resistance measurements throughout a field. The penetration resistance (60-152 kPa) recorded by the horizontal penetrometers were well correlated to those given by a Delmi penetrometer with correlation coefficients from 0.742 to 0.988.