Remote electronic acquisition of soil cone index measurement

Abstract

The cone penetrometer is widely used in tillage and off-road mobility research as an indicator of soil strength and density characteristics. Light-weight, manually operated units are especially useful in recording cone index determinations at remote field locations. Such units permit a single operator to measure and record penetration force vs depth in graphic form. However, the interpretation and analysis of such data has remained a tedious manual operation which has limited the number of determinations which are practical for a given field experiment. The system described in this paper allows one person to determine and electronically record penetration force vs depth relationships using a standard cone penetrometer (ASAE S313.1, 1979). A CMOS (complementary metal oxide semiconductor) microprocessor is utilized to sample and digitize analog signals and to record them on a magnetic tape cassette. An identifying code can be associated with each measurement and the microprocessor is subsequently utilized in interpreting cassette-stored data and transmitting it to a remote computer terminal or minicomputer for processing and analysis. Thus, this relatively low-cost system significantly enhances manual acquisition and interpretation of cone penetrometer measurements.