Resistograph
/ree-ZIS-toh-graf/🌲 Arboriculture●●● Advanced
A resistograph is a micro-drill resistance testing device that inserts a thin (1.5-3mm) needle into wood and measures the resistance encountered. The resulting graph shows peaks (sound wood) and valleys (decayed or hollow areas), allowing arborists to map the extent and location of internal decay. It is a minimally invasive Level 3 advanced assessment tool used in tree risk evaluations.
Etymology
From Latin resistere (to withstand) + Greek graphein (to write)
Example
“The resistograph trace showed a clear drop in resistance at 8 inches depth, indicating a decay pocket.”