Another great tool we have for detailed tree and decay assessment at Hayden’s is the IML PD500 Resistograph is a calibrated micro drill which measures the resistance to the progress of a 500mm long, 2mm diameter drilling needle bit as it enters the tree. The results of each measurement are produced in graphic form displayed two colours; blue represents the feed rate and green represents the penetration resistance. The graph is read from right to left and can be interpreted to evaluate relative wood strength, decay pockets, variations in ring growth, structural condition of cell walls and tree responses to environmental conditions. We also print off a hard copy on site for assistance in assessing the data on site and explaining it to the client.
The variation in resistance results in increases and decreases in the amount of torque applied to the drill shaft. By means of sophisticated mechanical and electronic sensors, variations in torque are translated into graphical output which depicts the internal conditions encountered by the drill at the specific point of drilling. Each of the drill tests undertaken is supplemented by a brief description of the analysis and discussed within the finished report.
The Resistograph is an invaluable tool especially when used alongside our Picus Tomograph to provide a detailed and valuable assessment of the structural integrity of the trees inspected.