The PiCUS TreeQinetic measuring system is used to perform tensile tests on trees. Tensile tests serve as part of detailed tree examinations to determine the break resistance and stability by measuring the tree’s reaction to an artificial wind substitute load.

There are two major types of tree failure: uprooting and breaking.

PICUS TreeQinetic system measures data that can help to assess uprooting and breaking safety. A known pulling load is applied to the tree with a winch assembly and inclinometers & elastomers record data to provide information on the root plate stability of the tree and resistance to bending of the stem. The TreeQinetic system uses wireless linked sensors for fast & easy recording & transmission of data. Please note that the pulling winch/cable is NOT supplied as part of the TreeQinetic and should be sourced separately.

Tree pulling tests were developed at the University of Stuttgart in the 1980’s and 90’s by a team led by Lothar Wessolly and Günther Sinn. The results can be evaluated according to Static Integrated Methods (SIM), e.g. the Elasto-Inclinomethod.

Statics integrating inspections are carried out with pulling tests (elasto-inclino method) that exert a wind substituting load on the tree using a winch and a steel cable. The reaction of the stressed trees under a defined load is measured with high resolution devices (Elastometer and Inclinometer) and the data obtained is compared with those of sound trees. In all safety calculations using the SIM, three major components are considered: wind-load, material properties of green wood and the surface of the load bearing structure (trunk diameter, extent of hollowness). Tree inspectors and practitioners may use a more simplified variation, the SIA method ( statics integrating assessment) which also follows international engineering conventions and allows for quick on-site-assessment.

PiCUS TreeQinetic Description

The tensile test with the PiCUS TreeQinetic provides you with all the measurement data you need to determine the root condition and the resistance to trunk breakage. During the tensile test, the tree is exposed to a defined equivalent wind load. The PiCUS TreeQinetic records three measured variables at the same time:

• Applied force
• Stretching or compression of the wood fibres
• Root plate inclination

To do this, the tree is pulled with a rope attached to the crown and with the help of a wrench. The load generated in this way and the reaction of the tree are measured with the Forcemeter, Inclinometer and Elastometer of the PiCUS TreeQinetic.

In this way, it is possible to determine how a tree behaves under load with a single measurement setup.

The various sensors of the PiCUS TreeQinetic

The inclinometer and elastometer sensor elements record the tree’s reaction to the load in different ways. The new Elastometer 3i can combine both technologies.

Inclinometer

The TreeQinetic inclinometers measure the inclination of the root plate and trunk under the tensile load. This can be used to evaluate the root stability and the anchoring force of the tree in the ground.

Elastometer

The elastometers record the elongation or compression of the outer wood fibres of the trunk. The measured values ​​serve as a basis for estimating the break resistance.

Elastometer 3i

In addition to the expansion or compression of the edge fibres, the new 3i elastometers can also measure the angle of the tree at its position and thus the inclination. The bending line and curvature of the tree can be calculated from the angle measurements at several positions. The bending line can, for example, help to better assess knot wounds.

PiCUS TreeQinetic range of functions:

Range: Action radius up to 60 m
Accuracy: Elastometer: 0.1 µm; Inclinometer: 0.005 °; Forcemeter: 0.3 kN
Connection: Wireless data transfer of all measurement data to the PC
Force build-up: A mechanical gripper pull with steel cable to build up the tensile force is optionally available in two variants
Expansion: The system can be upgraded with additional sensors at any time

The measuring principle:

During the tensile test, the tree is loaded by means of a rope that is attached to the crown and is pulled with a winch. The reaction of the tree to this load and the load itself are recorded: The TreeQinetic Forcemeter measures the force in the rope strand, while the TreeQinetic Elastometer measures the elongation or compression of the edge fibers of the trunk and the TreeQinetic Inclinometer measures the inclination of the root plate. These measured values are displayed live by the TreeQinetic software and saved after the test. For further evaluation, these values can be processed using additional software (arbostat, http://www.arbosafe.com). By comparing the tree reaction to a known equivalent load with the calculated load of an expected storm, a safety factor for breakage and stability is calculated.

Standard scope of delivery: