A novel device for detecting internal defects in wooden poles
R A Eaton, R S Johnstone
The diagnosis of internal defects caused by termites and decay in hardwood transmission poles has been investigated using a novel Automatic Feed Drill (AFD) pole testing device. Internal defects were recognised by changes in drill feed-rate as the automatic air-driven drill traversed its 100 mm working stroke. The instrument is portable, simple to operate and recognises defects instantaneously. Tests carried out on pole material in the laboratory and the field showed that the instrument gives quick and accurate measurements of internal collapse and weakness in wood at the groundline zone.