Ground evapotranspiration meter

The red curve represents the water potential at the bottom of the permeameter tank, while the yellow curve represents the water potential at the same depth in the field. The water level inside the tank always follows the changes in the water level in the field.

2. High precision "direct weighing" system:

At present, the commonly used method in China is the "indirect weighing" (lever type, suspension type) for steam permeation meters. The problem with the "indirect weighing" method is that it converts the large weight of the permeameter into a relatively small weight for measurement, and the creep during the conversion process cannot be eliminated, which affects the measurement accuracy; In addition, this weighing method has a very obvious delay, and the curve of weight increase does not coincide with the curve of weight decrease, which will cause great uncertainty for the high-resolution data required by the permeameter.

The SoilScope control type steam infiltration experimental system (weighing type underground steam infiltration instrument) adopts the "direct weighing" method. The use of direct weighing is due to the advancement of large tonnage weighing sensor manufacturing technology, with a maximum weighing range of 1200 tons and an accuracy of 1/10000. Combined with advanced weighing instruments, the weighing resolution reaches 1/100000, fully meeting the requirements of steam infiltration instrument weighing, and the evaporation resolution of the steam infiltration instrument reaches 0.01mm (1 square meter area steam infiltration instrument).

Not only can it measure vertical precipitation (rain, snow, etc.), but it can also accurately observe horizontal precipitation (frost, dew, etc.). It can obtain evapotranspiration and leakage under various climate and moisture conditions similar to those in the field, which can be used to accurately determine the groundwater recharge rate.

The nighttime evaporation data displayed in the red circle is opposite to that during the day, with an increase in tank weight, which is a phenomenon of condensation in the early morning of summer.

3. Groundwater level control system:

The traditional evapotranspiration monitoring system uses a Markov bottle for water replenishment, and the groundwater depth is fixed at a certain fixed depth, which cannot obtain the evaporation rate of groundwater at different depths in different seasons.

Our company has collaborated with research institutions to develop a utility model patent for the "Measurement and Control Device for Submersible Evaporation of Steaming Penetrating Instrument" (patent number: ZL201721092187.8), which has the following characteristics:

(1) Can control different groundwater depths arbitrarily. There are two control modes, namely automatic tracking and manual setting. Manually set a fixed water level, the water level balance system automatically controls the water pump, with a resolution of up to 0.001mm; the automatic tracking water level mode has a measurement accuracy of 0.2mm.

(2) Obtain the groundwater evaporation at different depths that vary with the seasons.

(3) High precision direct weighing sensors provide more accurate water supply and discharge, with an accuracy of 0.01mm (1 square meter).

(4) The integrated design of patented technology avoids errors caused by conventional measurement methods.

The purple horizontal line represents the artificially set groundwater level of 1500mm, while the red curve represents the actual water level fluctuating within 2mm around 1500mm.

4. Tank shape:

Previously, the permeameter mostly used "square tanks" and "backfill soil". The boundary effect of square tank bodies should affect the movement of soil moisture and the root growth of crops; The difference between backfill soil and the actual situation in the field is significant, and it takes a long time to approach the original soil, which affects the reliability of experimental data.

Now a "cylindrical" tank body is used, with uniform force in all directions and no dead corners for water transport.

The experimental soil column adopts "undisturbed soil column", and currently it is possible to obtain original soil columns of 2 square meters and 2 heights.

5. Installation method:

According to the on-site conditions of the user, different installation methods such as basement, maintenance well, and double sleeve are provided.

Installation and maintenance of basement well, double set simple installation
To achieve full functional monitoring, the temperature field variation of the experimental soil column needs to be small, and the monitoring function is relatively simple,
There are supporting basement facilities that occupy less land, have low cost, short construction period, and minimal interference to the surrounding area

6. EcoScope steam infiltration system software:

EcoScope, the control software for the steam infiltration center, is a professional ecological environment collection and calculation software independently developed and designed by Aozuo Ecological Instrument Company, with software copyright. Users can summarize the data of multiple permeameter columns in the software for analysis. Such as browsing the weight, flow rate, soil moisture, temperature, and EC data of each column; Display multiple or multi-layer sensor data for the same column on the same interface; Display calculated parameters such as ET, diving evaporation, etc.

The software adopts two data download methods: serial port (RS232) and Ethernet cable (TCP/IP). Data is automatically integrated and stored over time.

Based on the downloaded data, users can select some measurement parameters to generate a curve graph that supports dual Y-axis curves. Users can freely choose the measurement point data displayed on the screen at the same time.

Full Chinese interface.

Browse water level, soil moisture, temperature, and EC data for multiple columns

Browse the weight, flow rate, and leakage of multiple columns

Display soil parameters of the same column with multiple layers and different columns with the same layer on the same interface

Compare and display the water level, weight, flow rate, and leakage of different columns

Display calculated parameters such as ET and submerged evaporation rate