Dynamax Plant Stem Flow Monitoring System

system function

The use of thermal diffusion technology to measure plant stem flow velocity is particularly suitable for trees with thicker stems and tall plants. If used in conjunction with other sensors, it can measure plant stem flow under the influence of environmental factors such as air temperature and humidity, photosynthetically active radiation, soil temperature and humidity, etc.

Working principle

utilizeThe principle of Granier thermal diffusion sensor (TDP) is to directly insert two thermocouple probes into the edge wood. The upper probe contains an electric heater, and the lower probe serves as a reference to measure the temperature difference dT between the heating probe and the reference probe. Based on dT and dTm at zero stem flow, the Granier model can be applied to directly obtain the stem flow rate at each moment, and then the stem flow rate can be calculated based on the edge wood area.

For trees with consistent growth under a closed canopy, only one sensor is needed per tree. For irregular canopies or mixed tree species, the stem flow rate of large trees varies in different directions around the tree, and multiple sensors are required to accurately measure stem flow for a single tree. The diameter isTrees with a diameter of 75~150mm usually require 2 sets of sensors to be installed per tree; Trees with a diameter of 150-440 mm are equipped with 4 sets of sensors per tree.

System Characteristics

Dual probes,Granier Brick Design

The probe is easy to plug and can be reused

Constant temperature heating, using thermal diffusion method instead of the less accurate thermal pulse method

Continuous measurement is possible (thermal pulse method is not possible, there is a waiting period)

Application Cases

（1) Northwest A&F University Qinling

references

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