Plant multi-channel stem flow measurement system

1、 System Introduction

Plant multi-channel stem flow measurement systemComposed of MicroSet 8X control unit, SF81 stem flow sensor, and stainless steel heating electrode, it is used for monitoring stem flow of tree trunks with a diameter of 12cm or more, and synchronously monitoring the continuous growth of tree trunks. EMS81, as an independent and complete monitoring unit, can work independently to monitor the stem flow of a tree; Multiple units can also be selected to form a composite monitoring system that simultaneously monitors the stem flow and continuous growth of multiple trees at different distances. The entire composite system can be powered uniformly or each unit can be powered separately.

For large-diameter trees, relatively irregular tree trunks, or forest stands with extremely uneven soil moisture, such as tree trunks on slopes, it is recommended to select two stem flow monitoring units and install them in relative positions (such as sunny and shady). The average value measured will be used as the stem flow of the entire tree trunk.

2、 Working principle:

Plant multi-channel stem flow measurement systemAccording to the principle of thermal balance, THB (Tissue Heat Balance) heating technology directly heats the xylem inside the tree trunk, using the current flowing through the xylem between electrode plates to heat the woody tissue of the tree. The temperature of the electrode plates is monitored by a pin type temperature sensor, and the energy demand is proportional to the stem flow rate. The heating energy (mW) is converted into stem flow value through professional software. The principle of thermal equilibrium can be described as follows: the input energy is equal to the dissipated conduction heat and the increase in stem flow temperature, expressed by the following formula:

P = Q·dT·cw + dT·z

In the formula, P is the input energy (W), Q is the stem flow velocity (Kg/s), dT is the temperature difference at the measurement point (K), cw is the specific heat of water (J.kg1-K-1), and z is the coefficient of thermal conductivity loss at the measurement point (W.K-1). The THB method does not require any calibration and measures stem flow in kg/hr, making it suitable for observing stem flow in trees with a diameter of 12cm or more.

3、 Composition and classification:

1. EMS81 Growth and Stem Flow Measurement System - Microset8X Data Collector, Stem Flow Sensor (SF81), DRL26E Stem Continuous Growth Sensor (65mm), Stainless Steel Electrode, Protective Cover, Installation Tool, Waterproof Case.

2. EMS81 small stem network stem flow measurement system - SF8X data acquisition, N2N network output module, stem flow sensor (SF81), protective cover, stainless steel electrode, installation tool, waterproof chassis.

3、 Features and advantages

THB heating technology uses 3+1 electrode plates for direct heating, with high precision, stability, resolution, and low energy consumption. Energy consumption increases with stem flow, and there is no problem of overheating of tree trunk tissues

Each EMS81 can serve as an independent monitoring unit or form a composite multi-channel system to flexibly install and monitor stem flow and growth at different distances and in different forest stands, estimate transpiration and water flux

Minimum installed tree diameter 12cm

Data storage for 1 year (with a 10 minute collection interval)

Infrared data download, simple and easy to implement

Equipped with free software, it can set up data collection, download and display data charts and statistical analysis

3、 Technical parameters:

1TheSF81Stem flow sensor

1) Measurement range: 0~0.25 kg/h/cm

2)Electrode pads:25mm*1mm*60/70/80mm, corresponding to25mmThe35mmand45mmDepth of xylem, suitable for trees of different diameter classes

3）Electrode spacing:20mm

4）Temperature sensor: thermocouple,3+1Pin type, constant temperature difference1KThe2Kor3KCan be pre-set

5）3An electrode plate (with an insulated end) is used to conduct current to heat the wood around the electrode plate by heating the wood40－200AmOne electrode plate serves as a reference electrode (without an insulated end) and is installed at the lower end of the heating electrode100mmplace

6）Low energy consumption, average energy consumption0.3～0.4W@dT =1K，4W

7）Data: Average of measurements from three electrodes

2TheMicroset8Xdata collector

1）Power supply: rated voltage12VDCStarting voltage11.7VTurn off the voltage10V，working voltage16V，Tolerant voltage60V，current consumption400mA，Heating power 4W

2）Average work efficiency: greater than90%

3）Load resistance range:200Ω~25kΩ

4）Heating voltage:1kHzFrequency, non sinusoidal,150 Vef @25 kΩ

5）Average current consumption:20mA~50mA

6）Preset temperature control:1KThe2Kor3K

7）Working voltage range:7~16V

8）Data storage: solid-state storage,120000Each piece of data10It can be stored when stem flow and continuous growth of the tree trunk are collected once a minute1Annual data

9）Built in precision clock, clock accuracy±1Minutes per month, data charts with timestamps can be downloaded and browsed through professional software

10）Internal backup battery: lifespan10year

11）USB/IrDAInfrared data download, throughUSBConnecting with computers

12）Working temperature: -20~50°C

13）Specifications:0.5kg，160mm*80mm*60mm

14)Professional data download and analysis software that can directly provide the stem flow rate of tree trunks per unit circumference per hour（kg）, can perform data download, online data observation, bar chart, data repair, statistical analysis (such as hourly average, daily average, total, minimum value, etc.)Maximum value, data correlation analysis, regression analysis, chart display, and system settings, etc

Place of OriginCzech