Multi channel small stem flow measurement system

1、 Instrument Introduction

EMSMulti channel small stem flow measurement systemThe use of stem heat balance (SHB) principle to continuously and accurately measure plant stem flow is the stem flow measurement method specified in the "Forestry Industry Standard of the People's Republic of China - Long term Positioning Observation Method for Forest Ecosystems". The EMS62 system is more suitable for measuring stem flow in slender branches of trees or crops, and can be used for physiological research on crop cultivation, as well as physiological research on tree hydraulic structure and water management allocation.

2、 Working principle

EMSMulti channel small stem flow measurement systemThe stem flow sensor includes a protective shell composed of an anti radiation shell and insulation material, ensuring that the thermal balance is not too disturbed when used indoors or outdoors. EMS62 is commonly used to measure plants or organs with a diameter less than 20mm, such as twigs, seedlings, and crops. When installing, it is necessary to ensure good contact between the detector and the stem surface, and to ensure a length of 30cm.

The tree stem flow measurement system is based on the principle of heat balance (HB): the input energy is equal to the dissipated heat conduction and the increase in stem flow temperature. The specific formula is as follows:

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 loss at the measurement point (W.K-1).

The EMS62 measurement system has fixed dT and offers three dT values to choose from: 2K, 4K, or 8K, ensuring a constant heat loss that can be eliminated using a baseline. Calculating stem flow is not based on changes in temperature, but on changes in heating power.

3、 Composition and classification

1. EMS62 Small Stem Flow Measurement System - RB16 data acquisition, PMS14 power supply module, EMSS62B control module, stem flow sensor (SF62), protective cover, installation tool, waterproof chassis, optional GPRS, solar panel, and tripod.

2. EMS64 Small Stem Growth and Stem Flow Measurement System - Microset6X Data Collector, Stem Flow Sensor (SF64), PDS40P Stem Growth Sensor (5mm~40mm), Protective Cover, Installation Tool, Waterproof Case.

3. EMS64 small stem network stem flow measurement system - SF6X data acquisition, N2N network output module, stem flow sensor (SF64), protective cover, installation tool, waterproof chassis.

4、 Featured advantages

Forestry industry standard specifies measurement methods

Using feedback control, the temperature difference between the upper and lower probes is automatically controlled to be constant

The software can perform baseline calibration and directly output stem flow data

Long term continuous monitoring, uninterrupted monitoring, no need for duty

Equipped with protective devices, highly integrated, convenient for field installation and maintenance

5、 Technical parameters

1. EMS62/64 sensor

Ø Applicable diameters: 6-12mm and 12-20mm

Heating technology: external soft elastic heater

Ø Measurement module output: thermal power signal (mW/K)

Ø Software output: Stem flow rate (Kg/h · cm)

Ø Temperature sensor: specially designed thermocouple

Temperature difference: constant at 4K, 2K, or 8K

Ø Heater resistance: 100 ± 0.5 ohms

Heating current: 0.15A per channel (depending on stem flow rate)

Heating power: variable, 2W (depending on stem flow rate)

Operating temperature: -10~40 ℃

Measuring branches: requires a length of 30cm

Ø Weight: Sensor 0.1Kg

3. Data collector

Ø 16 channels;

Ø Accuracy: 0.03% of the measuring range;

Storage capacity: 512KB, approximately 220000 values (usable for more than 3 months);

Data collection interval: 10-2 minutes;

Storage interval: 10s-1hr;

4. Software

It can run on various versions of Windows systems and can be downloaded and upgraded from the website. Used for system settings, data storage, data analysis and processing, and output.

5. Power supply

12V DC lead-acid battery or power adapter

Origin: Czech Republic