A NEW HAND-HELD RECORDING PENETROMETER FOR SOIL STUDIES

This paper describes and evaluates a new solid-state recording hand-held cone penetrometer developed for in-situ soil studies. Force is measured by a strain-gauged transducer, and depth by an accurate optical system. Data for up to 20 penetrations per plot are stored and processed within the instrument in the field. The new penetrometer has been evaluated in field and soil tank experiments in comparison with three widely contrasting existing penetrometers ranging from a simple hand-held penetrometer to a trailer-mounted power-driven instrument. The results indicated that the simple hand-held penetrometer gave appreciably different cone resistance profiles from the other instruments. In particular, spurious ‘treatment effects’ obtained from the tillage experiment were shown to be due to inadequate instrument performance. The new solid-state recording hand-held penetrometer gave results comparable with those obtained from the more complex trailer-mounted instrument and another hand-held recording penetrometer.