The Centre Cone Penetrometer was developed as a low-cost instrument suitable for compaction studies. Simple in design, this hand-held penetrometer uses a helical compression spring to relate applied force to a linear scale. A sliding friction disc or rider allows an operator to keep track of the maximum force required to penetrate each depth interval. Use of a smaller-than-standard-diameter cone increases the range of mechanical impedance readings up to 110 bars.
Tests completed on the instrument indicate a force detection accuracy of ±5% of the full-scale reading. A side-by-side field comparison with a relatively expensive digital recording penetrometer showed a correlation of 0.99 when maximum readings were considered per depth interval.
It is hoped that the low cost and convenience of this instrument will allow compaction surveys to be carried out more efficiently.