An ultrasonic device for the measurement of working depths of cultivation implements /
Fisher, R.(Ron),author.
Rackham, D. H.,author.
Scottish Institute of Agricultural Engineering.
"Not for publication."--title-page.
"Scottish Institute of Agricultural Engineering."--at the head of the cover.
Report dated March 1983.
Includes bibliographical references (page 10).
Agricultural implements.
Ultrasonic testing