DR Radius Dendrometer
The DR series dendrometers are used for high-precision and continuous measurement of stem diameter changes. These devices are suitable for long-term use in outdoor conditions. Due to their extremely low power consumption, Ecomatik dendrometers are ideal for battery-powered solutions, e.g., in IoT applications. DR dendrometers are specially designed for tree trunks with medium to very large diameters (> 8 cm; or DR3, DR3W, DR6, DR7 > 5 cm). DR dendrometers are mounted with one (DR3, DR3W, DR6, DR7) or two special screws (DR1, DR1W, DR2, DR4) anchored in the tree stem. The changes outside the trunk wood correspond to then radial growth and the daily variation of the trunk diameter, which is associated with tree water status. Screw-mounting ensures extreme stability for long-term measurements with limited maintenance options. DR dendrometers are available in different versions:
- 11 mm Measurement Range (normal growth speed):
- DR1: with standard mounting frame and measuring range from of 11 mm for species with slow and average growth rates
- DR1W: hermetically sealed to withstand extreme environmental conditions (under snow cover, underwater, elevated exposure to dust and corrosive agents), with standard mounting frame, measuring range of 11 mm for species with slow and average growth rates
- DR3: quick assembly frame with only 1 screw, suitable for treediameters >5 cm, measuring range of 11 mm for species with slow and average growth rates
- DR3W: hermetically sealed to withstand extreme environmental conditions (under snow cover, underwater, elevated exposure to dust and corrosive agents), quick assembly frame with only 1 screw, for tree diameters >5 cm, measuring range of 11 mm for species with slow and average growth rate
- DR6: quick mount frame with only 1 screw for tool-less installation, suitable for treediameters >5 cm, measuring range of 25 mm for species with high growth rates
- 25 mm Measurement Range (high growth speed):
- DR2: with standard mounting frame and larger measuring range of 25 mm for fast-growing species
- DR6: quick mount frame with only 1 screw for tool-less installation, suitable for treediameters >5 cm, measuring range of 25 mm for species with high growth rates
- 50 mm Measurement Range (very high growth speed):
- DR4: with standard mounting frame and even larger measuring range of 50 mm for very fast-growing species
Advantages of the DR series
- Suitable for large stem diameters (> 8cm)
- Minimal contact pressure on tree trunk surface
- Maximum stability against wind, snow, falling branches and fruit
- Ideal for long-term measurements with limited maintenance work
Specific to the DR2 model
- Extended measuring range; reduced maintenance effort (i.e. longer time interval between readjustment of the dendrometer frame) for fast-growing species
Specific to the DR3 & DR3W models
- Quick mounting frame with only 1 screw
- Can be used for trunk diameters >5 cm
Specific to the DR1W & DR3W models
- Hermetically sealed to withstand extreme environmental conditions: e.g. high humidity, underwater, below snow cover, near the ground surface, elevated exposure to dust or corrosive agents (e.g. coastal sands, volcanic ash), etc.
Limits of the DR rangeseries
- Drilling and installing the anchoring screws in the trunk may injure the tree (the damage can be minimized by using wound closure resin)
- Not suitable for small trunk diameters (<8 or < 5 cm)
Models
Model Name | For Diameter | Measurement range |
---|---|---|
DR1 | > 8 cm | 11 mm |
DR1W (sealed) | > 8 cm | 11 mm |
DR3 (quick mount frame, 1 screw) | > 5 cm | 11 mm |
DR3W (quick mount frame, 1 screw, sealed) | > 5 cm | 11 mm |
DR7 (quick mount frame, 1 screw) | > 5 cm | 11 mm |
DR2 | > 8 cm | 25 mm |
DR6 (quick mount frame, 1 screw) | > 5 cm | 25 mm |
DR4 | > 8 cm | 50 mm |
Technical data
Sensor Name | Radius Dendrometer | Radius Dendrometer | Radius Dendrometer | Radius Dendrometer | Radius Dendrometer |
Application Area | Slow/normal growing | Slow/normal growing | Slow/normal growing | Fast growing | Very fast growing |
Suitable for | Diameter: > 8 cm | Diameter: > 5 cm | Diameter: > 5 cm | DR2: Diameter: > 8 cm DR6: Diameter: > 5 cm | Diameter: > 8 cm |
Special Feature / Limitation | Attachment with 2x trunk screws; DR1W: encapsulated with extended range of use, see operating conditions below. | Attachment less invasive with only 1 trunk screw; dual-point installation possible: separate measurement of wood and bark (requires 2 DR3 sensors); DR3W: encapsulated with extended range of use, see operating conditions below. | Attachment less invasive with only 1 trunk screw; Tool-free installation | DR2: Attachment with 2x trunk screws DR6: Attachment gentler with only 1 trunk screw; installation tool-free | Attachment with 2x trunk screws |
Measurement Range | 11 mm linear | 11 mm linear | 11 mm linear | 25.4 mm linear | 50.8 mm linear |
Resolution | Data logger dependent, e.g.: | Data logger dependent, e.g.: | Data logger dependent, e.g.: | Data logger dependent, e.g.: | Data logger dependent, e.g.: |
Accuracy | Dendrometer dependent: max. ± 4.5% of the measurement value (stable offset) | Dendrometer dependent: max. ± 4.5% of the measurement value (stable offset) | Dendrometer dependent: max. ± 4.5% of the measurement value (stable offset) | Dendrometer dependent: max. ± 1.97% of the measurement value (stable offset) | Dendrometer dependent: max. ± 0.98% of the measurement value (stable offset) |
Operating conditions | All Models: Sealed Model DR1W: | All Models: Sealed Model DR3W: | All Models: | All Models: | Temperature range: -40 to +60°C |
Weight (sensor only, without cable) | 15 g (DR1), 30 g (DR1W) | 30 g | 35 g | 43 g | |
Power supply | Vex (! regulated !) 0.5 to 10 VDC, | Vex (! regulated !) 0.5 to 10 VDC, | Vex (! regulated !) 0.5 to 10 VDC, | Vex (! regulated !) 0.5 to 10 VDC, | |
Material | Rostfreier Stahl und Aluminium | Rostfreier Stahl und Aluminium | Rostfreier Stahl und Aluminium | Rostfreier Stahl und Aluminium | |
Sensor cable length | 5 m, extendable to max. of 100 m | 5 m, extendable to max. of 100 m | 5 m, extendable to max. of 100 m | 5 m, extendable to max. of 100 m |