What is a Resistograph

The Resistograph^® is a sophisticated electronically controlled drill that provides unsurpassed accuracy in measuring the relative density of wood in trees and timber structures. The Resistograph^® was invented by Frank Rinn and this new series brings his decades of research and experience to the fore with practical design features that reflect user needs.

The Resistograph^® Series 650 is an extremely powerful machine. It is very fast, easy to use, dependable in all weather conditions, and very accurate. With fully electronic motors that automatically match feed rates and drilling speeds to actual wood conditions, this is the machine that delivers consistently reliable results. No need for complex output charts, you can watch the output results live on a smartphone, tablet, or printer as the drilling takes place. On your laptop, tablet or desktop use the sophisticated DECOM software to analyze the data and produce credible charts that properly reflect actual wood conditions.

Why carry out Resistograph testing ?

In some instances it may be necessary to go beyond a basic visual inspection of a tree. In such cases we may recommend the use of a Resistance micro drill. This tool utilises a very fine drill to measure the resistance encountered within the wood and can therefore provide a relative assessment of the presence of degraded wood and its extent which could affect the structural integrity of the tree.

In some cases it may not be appropriate to use a micro-drill or there can be disadvantages in using such a technique so sonic tomography or another non-invasive method would be recommended. 

This system can be used in a number of contexts, for instance:

• To inform the risk management of individual trees,
• Providing evidence to support TPO applications,
• To inform the management of aged or veteran trees,
• To provide a baseline for the monitoring of progressive decay.