Fruit and Vegetable Dendrometer
The operation of the Ecomatik DF dendrometer is based on the variation of an internal resistance with the pressure that the growing of a fruit or vegetable exerts on the sensor. The fruit in the measuring frame is fixed without affecting its growth. The frame bears the weight of the target.
The hardware includes components for use on things like citrus or apples, gourds or zucchini, and even small fruits like grapes. Note however that this dendrometer should not be used on extremely soft fruits, e.g. ripe tomatoes.
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.
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.
Fruit Diameter Sensor Features
- Suitable for diameter up to 11 cm
- Fruit/vegetable does not have to bear the weight of the dendrometer
- Measures diameter changes
- No injury to plants
- Minimal load on the target
- Stability against wind, snow, falling small branches and small fruits
- Ships with 2m cable, fixing materials and installation tools
- Range of sensor: 15mm
- Accuracy: ±2µm (±0.12%) possible with good data logging hardware
- Resolution: 0.3 to 3.6 µm, dependent on data logging hardware
- 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.