Root and Aquatic Plant Dendrometer (DRO)

The DRO is designed for continuous measurements on roots, aquatic plants and creepers. A soft, resistant rubber coating protects the whole sensor and the sensor rod from ingress of moisture and solid particles, the device is waterproof. If needed, a metal clamp protects the sensor rod from excessive pressure exerted from overlying soil. The specific weight of the unit is equivalent to that of water. When used underwater, no extra load is charged on target plants by the floating instrument. It is easy to install and maintenance free. Its suitability has been proven in long-term tests (> 1 year) under below ground field conditions.


  • Waterproof, suitable for use in/on the soil and under water
  • Floating underwater, no extra load on target plants
  • Low pressure at the measuring point
  • Ideal for long-term measurements


  • Only for diameter smaller than 2 cm


  • Complete with 5 m cables

Options / Ordering Information

  • Cable extension (please specify in meters)
  • Data Logger

Root and Aquatic Plant Dendrometer (DRO)

Technical specifications

Name Root and aquatic Plant Dendrometer (DRO)
Suitable for diameter 0-2 cm
Range of the sensor 11 mm
Accuracy ±1.5 µm ± 0,12% (CR1000 Logger)
Resolution 0.2-2.6 µm (dependent on used data logger)
Linearity 1%
Thermal expansion coefficient of the sensor <0,2 µm/K
Operating conditions -25 to 70 °C air temperature, 0 to 100% relative air humidity