Stem Dendrometers.



  • The Implexx Small Stem Dendrometers are ideal for irrigation and scientific research;
  • Model SD-5T: stems 5 to 25 mm diameter;
  • Model SD-10T: stems 20 to 70 mm diameter;
  • Low cost, high accuracy dendrometers;
  • SDI-12 digital output for data loggers, LoRaWAN and internet enabled devices;
  • 0.001 mm resolution for precision measurements;
  • Easy to install and very low ongoing maintenance.


The SD-5T and SD-10T utilise state-of-the-art technology for precision measurements of stem growth dynamics. The dendrometers are suitable for growers monitoring crops as well as advanced scientific research projects.

With a measurement resolution of 0.001 mm, the SD-series of dendrometers can measure and monitor micro-variations and growth in small or herbaceous stems.

The dendrometers are currently being used by scientists from the US Forest Service, University of Melbourne, University of Queensland, NSW Department of Primary Industries, and more.

The dendrometers are also extremely popular with growers with many sensors deployed on crops such as almonds, grapevines, mangoes, macadamias, and more.

The SD-type sensor consists of an LVDT probe mounted in special fixing brackets and a DC powered signal conditioner.

SD-5T and SD-10T models have different fixing brackets for the same 5 mm LVDT probe. The SD-5T bracket fits stems with 5 to 25 mm in diameter. The SD-10T bracket is suitable for 20 to 70 mm stems.


Ideal for Internet Enabled Devices and Remote Field Monitoring

The SD-5T and SD-10T Dendrometers are ideal for IoT devices and remote field monitoring because:

  • It operates via the SDI-12 protocol which is supported by a wide range of data loggers and telemetry units;
  • It has low power requirements and can be supported off small batteries;
  • It is quick to install (less than a few minutes) and ongoing maintenance is minimal.

The team at Implexx can provide data loggers and telemetry devices. Our international network of accredited dealers and agents also have a range of data acquisition options that may be unique to your specific location. Otherwise, we can assist in connecting our dendrometers to your existing irrigation monitoring or data acquisition system.


Irrigation Monitoring, Carbon Allocation, Growth Rates, and More

The SD-5T and SD-10T are suitable for a wide range of applications including:

  • Irrigation monitoring and scheduling;
  • Fertigation or nutrient monitoring and scheduling;
  • Carbon allocation, biomass accumulation and relative growth rates;
  • Maximum Daily Shrinkage (MDS) and other calculated variables.


More Information

Dendrometer Data Fruits

Figure 1A. Three days of dendrometer data.

Plant growth and water balance affect diurnal behaviour of trunk radius. The growth rate depends on a vegetation stage and environmental conditions. The diurnal variations represent mostly fluctuations of water content in plants. Two radius-based indices are commonly used for evaluating plant water status: daily contraction amplitude and trend of daily maxima. The DE-1T Dendrometer allows investigating effects of irrigation rate and other environmental factors on water balance and growth of plants.

The SD-5T and SD-10T Dendrometer includes a linear displacement transducer (LVDT) mounted on a special rod with threaded end. When the rod is anchored inside the trunk, the LVDT represents the movement of trunk surface. Thus, the output signal follows variations of distance between trunk surface and the end of the rod, which is anchored inside the trunk.

A signal conditioner provides excitation of the LVDT and production of standard linear output signal.

The probe is connected by a standard 1-meter cable to the waterproof box with the signal conditioner inside.

The output cable length should be specified in the order if required.



Feature Specification
Stem Diameter Range SD-5T: 5 to 25 mm | SD-10T: 20 to 70 mm
Measurement Range SD-5T: 0 to 5 mm | SD-10T: 0 to 10 mm
Resolution 0.001 mm
Accuracy 0.002 mm
Output SDI-12
Supply Voltage 5 to 24 VDC
Operating Temperature 0 to 50 ℃
Temperature Effect < 0.02 % total stroke / ℃
Excitation Time 5 seconds
Cable length between probe and signal conditioner 1 m
Cable length between conditioner and logger 5 m (standard) | 60 m (maximum)
Warranty 1 year

Manual & Docs



Application Notes and Articles


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