Old Courthouse Oak, Resistograph readings

10/22/09Performed by :

A.D. Ali PhD, BCMADavey Institute

Resistograph• The resistograph is an instrument that detects decay and cavities

in trees and timber. Through resistograph technology, an arborist is able to detect wood decay, stages of rot, hollow areas, cracks and ring structure. The resistograph is an ideal device for estimating tree stability and longevity. The resistograph is based on a drilling resistance measuring method developed by Frank Rinn in Heidelberg, Germany.

As the micro drill enters the tree, the resistance of the wood changes the rotation speed of the drill. These variations are translated into a graph, which looks a lot like an EKG print out. The tiny drilling hole closes itself up without any damage to the tree.

• The resistograph is fast, accurate and reliable. Its biggest advantage is that it detects decay with virtually no tree damage. It also enables an arborist to analyze annual ring structures and to determine the growth tendency according to the width of annual rings. Its efficiency and reliability make it easy for homeowners to use.

Live Oak base, West and East

0”1”2”3”4”5”10” 8” 7” 6”9”14” 13” 12” 11”17” 16” 15”19” 18”

0”1”2”3”4”5”10” 8” 7” 6”9”14” 13” 12” 11”17” 16” 15”18”

Live Oak base, South

0”1”2”3”4”5”10” 8” 7” 6”9”14” 13” 12” 11”17” 16” 15”18”19”

Live oak, branch A

3” 2” 1” 0”4”5”8”9” 7” 6”10”11”12”

AB

BA

Live oak, branch A & B

3” 2” 1” 0”4”5”8”9” 7” 6”10”11”12”

3” 2” 1” 0”4”5”8”9” 7” 6”10”11”12”

Live oak, branch C

3” 2” 1” 0”4”5”8”9” 7” 6”10”11”12”13”

Live oak, branch D

3” 2” 1” 0”4”5”8”9” 7” 6”10”11”12”13”

Live oak, branch E

3” 2” 1” 0”4”5”7” 6”

Live oak, branch F

3” 2” 1” 0”4”5”8”9” 7” 6”10”11”12”13”