There are currently several invasive instruments on the market for detecting wood rot in wooden poles used by the distribution network operators (DNOs) which are based on both acoustic (hammer in nail, tap and listen) and ultrasonic (slice shadow) technologies. Current products on the market adopt a variety of techniques but all are restricted to detecting rot in very close proximity to the point at which the measurements are being taken.

To satisfy the DNOs objective of assessing the condition of their pole assets, there is a need for an instrument that is easy to use in the field, takes non- intrusive measurements, and has the ability to operate at ground level over the entire length of the pole. Such an instrument would prevent the need for digging around the base of the pole disturbing previously good ground conditions, or climbing the pole to make measurements at height. This project is to conduct a study into the feasibility for such a device.

Objectives

Ultrasound can be used to detect changes in wood density which results in an acoustic path impedance variation between different wood densities. This change can be caused by rotted fibres within the pole, or other features such as drilled holes etc. This density change produces a discernible energy reflection at the boundary which can be analysed and visualized in an instrument. Current techniques use ultrasound to analyse cross sections of the pole, ‘slices’, which are normally at ground level. This project aims to develop a technique to use ultrasound longitudinally and thus from one point access the top and bottom of the pole.