The DV dendrometer is designed to continuously measure vertical changes (not growth) of trees. Tree stems and their respective sections vary in length and curvature, according to water status (short- to mid-term), wind direction and wind speed (short-term to permanent), snow and fruit load (mid-term to permanent), and unbalanced growth or loss of crown parts (long-term to permanent). Transcription of vertical changes, along with their directional information, provides valuable information to assess water status and static properties of a tree (stress-strain relationship, mechanical load/stability, etc.). Parallel measurements with three vertical dendrometers (each oriented in three different cardinal directions) are necessary for a complete overview of vertical changes.
Advantages
- Stress-strain relationship computation
- Maximum stability against wind, snow, falling branches and fruit
- Ideal for long-term measurements
Limits
- Installation (drilling and screwing in the anchoring screws) damages the tree trunk (which could be minimized with wound closure resin).
- Only suitable for diameters > 8 cm
Technical data
Sensor model name
Vertical Dendrometer
Type DV
Scope of application
Stems or branches
Suitable for diameter
5 – 32 cm
Special features/limitations
2x trunk screws for mounting
Measurement range
11 mm linear
Resolution
Data logger dependent e.g.:
CR300 series: 0.01 µm
Dendrometer logger DL18: 0.2 µm
Accuracy
Dendrometer dependent: max. ± 4.5% of the measured value (stable offset)
Data logger dependent e.g.:
CR300 series: ± (0.04% of the measured value + 0.3 µm)
Dendrometer logger DL18: ± (0.1% of the measured value + 0.45 µm)
Output signal
Analogue, 0V to Vex (excitation supply voltage)
Temperature drift of the sensor
< 0.2 µm/°C in the whole measurement range
Temperature coefficient of the stem embracing cable wire
< 1.4 ×10-6/K
Linearity
< 1%
Operational conditions
Normal outdoor field conditions, -25 to 70 ° C, 0 to 100% relative air humidity; unsuitable underwater and below snow cover
Weight (sensor without cable)
13 g
Power supply
Vex (! stabilized !) 0.5 to 10 VDC,
Power consumption max. 0.28 µWh per measurement
Material
Stainless steel and aluminium
Accessories & Compatible Products
Data loggers
From small and compact to an extensive measuring network, Ecomatik offers complete system solutions for sensor data acquisition in any desired size:
- Mini-Systems (e.g. DL18)
- Maxi-Systems (e.g. Campbell data logger station)
Note
The output signal of all Ecomatik dendrometer models is an analogue DC voltage. Our dendrometers are therefore compatible with almost all common data loggers and microcontrollers with analogue voltage input channels (e.g. also Arduino). If you are unsure about the compatibility of an existing data logger, please do not hesitate to contact us.
