The Digitech Keyboard

Series 5 Manual Band Dendrometer, High Tension

For trees over 20” dia.

Trunk circumference contracts daily during morning and early afternoon as storage water moves out of the trunk to the crown. In late afternoon and evening, the trunk expands as root water recharges the storage volume in the trunk. When this cycle begins to decrease in magnitude, the tree is under water stress. Seasonally, the trunk slowly forms a ring of wood. Band dendrometers can determine when and how much wood is formed. Once the yearly pattern is established, deviations from this pattern due to fertilizer, water or sickness can be determined, often before visual symptoms appear. The dendrometer is constructed of stainless steel and brass with a UV-stabilized nylon thumb screw. Consists of the band around the circumference of the trunk (can be applied to trunk diameters of 1” and larger) and a method of measuring very small changes in the length of the band. The method consists of two metric (millimeter) scales. One scale is fixed. The second scale is attached to the band and moves as the tree expands and contracts. For advanced users, the dendrometer can also be used with a digital caliper to achieve a ten fold increase in resolution over visual readout. Two constant band tension levels available: low tension for trees up to 20” in diameter and high tension for trees over 20” in diameter.