The operation of the Ecomatik DC2 dendrometer is based on the variation of an internal resistance with the pressure that the growing of a tree trunk exerts on the sensor. The sensor is mounted on a wire cable with very low thermal expansion coefficient at the tree. Its slide rings reduce the friction between the wire cable and the tree bank, and decrease the pressure on the tree.
To acquire the most accurate and stable measurements, you should read the resistance from the sensor via I2C bus in a full-bridge configuration through a 16-bit analog-to-digital converter whose reference is provided by a high-precision 3V voltage reference. Note: This sensor only works reliably on tree trunks that are relatively round. Do not use it on misshapen oblong trunks.
What is a dendrometer? Dendrometers are instruments for continuous measurement of plant growth (changes of the plant diameter). Data from a dendrometer document the reactions of plants to the environment in a high temporal resolution.
In ecophysiological research, environmental parameters are measured hourly or shorter. The plant parameters such as yield, biomass and tree rings are only available annually. It is quite difficult to compare hourly data with annual data. Significance of such cause-effect studies on different time scales is limited.
A dendrometer allows you to record the plant parameters at the same time interval as environmental parameters. The data therefore permit the direct correlation of plant responses to environmental influences. This makes dendrometers useful for ecophysiological studies.
Trunk Diameter Sensor Features
- Suitable for all tree sizes over 5cm diameter
- Pressure of the wire cable to the three independent of tree size
- Automatic adjustment of the tension; sensitive measurements even with very large trees
- No injury to plants
- Stability against wind, snow, falling small branches, or small fruits
- Easy installation
- Easy adjustment via integrated turnbuckle
- Ships with 2m cable and 1m wire
- Range of sensor: 15mm
- Range of dendrometer with reset: Unlimited
- Range of dendrometer without reset:
For tree diameter of 10cm: 9.9mm in diameter
For tree diameter of 50cm: 6.6mm in diameter
For tree diameter of 100cm: 5.2mm in diameter
- Accuracy: ±2µm (±0.12%) possible with good data logging hardware
- Resolution: 0.3 to 3.6 µm, dependent on data logging hardware
- Linearity: 2%
- Thermal expansion coefficient of wire cable: less than 1.4 × 10-6/K
- Thermal expansion coefficient of the sensor: less than 0.1µm/K
- Operating conditions: -30 to +40 °C; 0-100% RH
- Output resistance: 0 to 20 kΩ
Compatible with Waspmote This sensor can be used in a Waspmote wireless sensor platform by plugging it into the Waspmote Agriculture Sensor Board PRO.