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 DC3, > 5 cm). DR dendrometers are mounted with one (DR3, DR3W) or two special screws (DR1, DR2, DR1W) 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 treewater status. Screw-mounting ensures extreme stability for long-term measurements with limited maintenance options. DR dendrometers are available in five different versions:

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. DR2: with standard mounting frame and larger measuring range of 25 mm for fast-growing species
4. 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
5. 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 rates

Advantages of the DR series

  • Suitable for large stemdiameters (> 8cm)
  • Minimal contact pressure on treetrunk 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 usedfortrunk 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 installingthe anchoring screws in the trunk may injure the tree (the damage can be minimized by using wound closure resin)
  • Notsuitable for smalltrunk diameters (<8 or < 5 cm)

Models

Model nameSuitable for diametersMeasurement range
DR1> 8 cm11 mm
DR1W (gekapselt)> 8 cm11 mm
DR2> 8 cm25 mm
DR3 (Schnellspannrahmen, 1 Schraube)> 5 cm11 mm
DR3W (Schnellspannrahmen, 1 Schraube, gekapselt)> 5 cm11 mm

Technical data

Sensor model name

Radius dendrometer Type DR1 and DR1W (hermetically sealed)

Radius dendrometer
Type DR2

Radius dendrometer
Type DR3 and DR3W (hermetically sealed)

Scope of application

Slow/average growth ratesFast-growingslow/normal growth rates

Suitable for diameter

> 8 cm

> 8 cm

> 5 cm

Special features/limitations

2x trunk screwsfor mounting

Extended measurement range for fast-growing species,

2x trunk screwsfor mounting

Only 1 trunk screwfor mounting, less invasive; dual point installation possible: separate measurement of wood and bark (requires 2 DR3 sensors)

Measurements range

11 mm linear

25,4 mm linear

11 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: 0.03 μm

Dendrometer logger DL 18: 0.5μm

Data logger dependente.g:

CR300 series: 0.01μm

Dendrometer logger DL18: 0.2μm

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)
Dendrometer dependent: max. ± 1.97% of the measured value (stable offset)
Data logger dependent e.g: CR300 series: ± (0.04% of the measured value +0.6μm)
Dendrometer logger DL18: ± (0.1% of the measured value +1 μm)

Dendrometer dependent: max. ± 4.5% of the measured value (stable offset)

Data logger dependente.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)

Analogue, 0V bis Vex (excitation supply voltage)

Analogue, 0V to Vex (excitation supply voltage)

Temperature drift of the sensor

< 0.2 µm/°C in the whole measurement range

< 0.2 µm/°C in the whole measurement range

< 0.2 μm/°C in the whole measurement range

Linearity

< 1%

< 0,7%

< 1%

Operational conditions

All Models:

normal outdoor field conditions, -25 to–70 °C, 0 to–100% relative air humidity;

Hermetically Sealed Model DR1W:

even under extreme environmental conditions (underwater, below snow cover, under exposure to strongly corrosive substances e.g. saltwater, ash, aggressive agricultural chemicals)

All Models:

normal outdoor field conditions,-25 to 70 °C, 0 to 100% relative air humidity

All Models: normal outdoor field conditions, -25 to70 °C, 0 to 100% relative air humidity;

Hermetically Sealed Model DR1W:

even under extreme environmental conditions (underwater, below snow cover, under exposure to strongly corrosive substances e.g. saltwater, ash, aggressive agricultural chemicals)

Weight (sensor without cable)

13 g (DR1), 17 g (DR1W)

33 g

13 g

Power supply

Vex (! stabilized!) 0.5 to 10 VDC,

Power consumption max. 0.28 μWh per measurement

Vex (! stabilized!) 0.5 to 10 VDC, Power consumption max. 0.28 μWh per measurementVex (! stabilized!) 0.5 to 10 VDC, Power consumption max. 0.28 μWh per measurement

Material

Stainless steel and aluminiumStainless steel and aluminiumStainless steel and aluminium

Sensor cable length

5 m, extendable on request to max. 100 m

5 m, extendable on request to max. 100 m5 m, extendable on request to max. 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:
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.

Contact

You need a quotation, have questions about a product, or need extensive technical advice in the context of your project planning. Starting with an initial determination of your needs, through the detailed planning of the required measurement equipment and data transmission technology, up to professional implementation on site, we are at your disposal at any time with advice and action.

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Assessment of your needs

With your consideration and input, we determine which of our products best meet your needs. We are also happy to design fully-integrated measuring stations (plant, climate, soil sensors), including an independent power supply and mobile data transmission, depending on your requirements.

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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...