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):
  1. DR1: with standard mounting frame and measuring range from of 11 mm for species with slow and average growth rates
  2. 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
  3. 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
  4. 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
  5. 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):
  1. DR2: with standard mounting frame and larger measuring range of 25 mm for fast-growing species
  2. 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):
  1. 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 cm11 mm
DR1W (sealed)> 8 cm11 mm
DR3 (quick mount frame, 1 screw)> 5 cm11 mm
DR3W (quick mount frame, 1 screw, sealed)> 5 cm11 mm
DR7 (quick mount frame, 1 screw)> 5 cm11 mm
DR2> 8 cm25 mm
DR6 (quick mount frame, 1 screw)> 5 cm25 mm
DR4> 8 cm50 mm

Technical data

Sensor Name

Radius Dendrometer
Type DR1 and DR1W (encapsulated)

Radius Dendrometer
Type DR3 and DR3W (encapsulated)

Radius Dendrometer
Type DR7

Radius Dendrometer
Type DR2 and DR6

Radius Dendrometer
Type DR4

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.:
CR300 series: 0.01 µm
Dendrometer Logger DL18: 0.2 µm

Data logger dependent, e.g.:
CR300 series: 0.01 µm
Dendrometer Logger DL18: 0.2 µm

Data logger dependent, e.g.:
CR300 series: 0.01 µm
Dendrometer Logger DL18: 0.2 µm

Data logger dependent, e.g.:
CR300 series: 0.03 µm
Dendrometer Logger DL18: 0.5 µm

Data logger dependent, e.g.:
CR300 series: 0.05 µm
Dendrometer Logger DL18: 1 µm

Accuracy

Dendrometer dependent: max. ± 4.5% of the measurement value (stable offset)
Logger dependent, e.g.:
CR300 series: ± (0.04% of the measurement value + 0.3 µm)
Dendrometer Logger DL18: ± (0.1% of the measurement value + 0.45 µm)

Dendrometer dependent: max. ± 4.5% of the measurement value (stable offset)
Logger dependent, e.g.:
CR300 series: ± (0.04% of the measurement value + 0.3 µm)
Dendrometer Logger DL18: ± (0.1% of the measurement value + 0.45 µm)

Dendrometer dependent: max. ± 4.5% of the measurement value (stable offset)
Logger dependent, e.g.:
CR300 series: ± (0.04% of the measurement value + 0.3 µm)
Dendrometer Logger DL18: ± (0.1% of the measurement value + 0.45 µm)

Dendrometer dependent: max. ± 1.97% of the measurement value (stable offset)
Logger dependent, e.g.:
CR300 series: ± (0.04% of the measurement value + 0.3 µm)
Dendrometer Logger DL18: ± (0.1% of the measurement value + 0.45 µm)

Dendrometer dependent: max. ± 0.98% of the measurement value (stable offset)
Logger dependent, e.g.:
CR300 series: ± (0.04% of the measurement value + 0.12 µm)
Dendrometer Logger DL18: ± (0.1% of the measurement value + 0.2 µm)

Operating conditions

All Models:
Temperature: -25 to +70 °C
Humidity: 0 to 100 % rH

Sealed Model DR1W:
Also under extreme environmental conditions (underwater, below the snow cover, highly corrosive substances such as seawater, ash, aggressive agricultural chemicals)

All Models:
Temperature: -25 to +70 °C
Humidity: 0 to 100 % rH

Sealed Model DR3W:
Also under extreme environmental conditions (underwater, below the snow cover, highly corrosive substances such as seawater, ash, aggressive agricultural chemicals)

All Models:
Temperature: -25 to +70 °C
Humidity: 0 to 100 % rH

All Models:
Temperature: -25 to +70 °C
Humidity: 0 to 100 % rH

Temperature range: -40 to +60°C
Working temperature: -20 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,
Consumption max. 0.28 µWh per measurement.

Vex (! regulated !) 0.5 to 10 VDC,
Consumption max. 0.28 µWh per measurement.

Vex (! regulated !) 0.5 to 10 VDC,
Consumption max. 0.28 µWh per measurement.

Vex (! regulated !) 0.5 to 10 VDC,
Consumption max. 0.28 µWh per measurement.

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

Manuals

Technical data sheets

Special information for integrators & developers

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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:

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.

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Like so many things, everything started with an idea ...

In the case of the plant scientist and founder of ECOMATIK, Dr. Liu, it was the idea that modern measurement technology should enable crucial plant physiological parameters to be measured directly, precisely and with high temporal resolution on the plant itself. It was obvious to him that there is an information potential of immense value in the detailed understanding of immediate reactions of plants to their environment...