Soil evapotranspiration monitoring instrument

Instrument usage

Soil evapotranspiration monitoring instrumentIt is a more systematic and comprehensive standard experimental equipment developed and produced by our company based on the continuous development of modern electronic technology, soil physics, microclimate and other disciplines, for the determination of transpiration and evaporation in farmland and groundwater soil water conversion. The instrument adopts a high-resolution weighing system, equipped with intelligent data collectors and signal sensors, which can simultaneously detect small changes in soil moisture transpiration, evaporation, leakage over time, as well as corresponding parameters such as temperature, air humidity, light, precipitation, etc. The measured data is analyzed, processed, recorded and stored in real-time online, achieving high-speed, accurate and user-friendly data collection, greatly improving work efficiency and reducing labor intensity. Suitable for long-term monitoring of hydrological cycles in ecosystems such as farmland, grasslands, forests, and river wetlands.

A group device based on the principle of water balance to directly measure surface evapotranspiration can achieve accurate measurement of rainfall, evapotranspiration, and drainage; Various types of sensors can be selected for research needs in the fields of water balance, material balance, soil solute transport, etc.

Soil evapotranspiration monitoring instrumentInstrument composition

Outer bucket (diameter 60CM, total height 80CM), made of stainless steel material;

Inner bucket (diameter 30CM, depth 60CM), made of stainless steel material;

Weighing platform, made of stainless steel material;

Water blocking ring, made of stainless steel material;

High precision weighing sensor;

Subsurface water sensor;

Drainage pump;

Assemble the instrument

1. The inner bucket, weighing platform, weighing sensor, and seepage sensor have been assembled in one unit, making it convenient for on-site installation;

2. Drainage pump: External installation, can be mounted to a bracket or pole using a U-shaped buckle, powered by 12V;

3. Installation of drainage pipe: One end of the inlet pipe is connected to the bottom of the outer bucket, and the other end is connected to the pump inlet; Water outlet pipe, one end connected to the pump outlet and the other end led to the outside of the waterproof box for drainage;

4. Water seepage sensor: tipping bucket type, integrated into the weighing base;

5. Weighing sensor: 0-1000kg, 6-wire system, integrated into the weighing base;

6. Rubber sealing ring: used to seal the connection between the top ring and the outer bucket;

7. Cover of the evaporator: equipped with a sealing collar to prevent debris or water from entering the evaporator;

8. Sensor cables and pumping pipes are connected to the data acquisition system and water pump through waterproof connectors on the upper cover;

Product Technical Parameters

1. Water seepage sensor: switch signal, can be connected to a data acquisition instrument for recording, 6.28ml/bucket; Signal line, red and green;

2. Weighing sensor:

Definition of signal line:

Red - SIG+White - SIG - Bare Wire - SHD Yellow - SEN+Green - EXC+Brown - SEN - Black - EXC-

4. Data acquisition device

Core: ARM 32-bit Cortex-M3 CPU

System clock: up to 72MHz

Instruction execution speed: 1.25 Dmips/MHz

Sampling frequency: 0.5/s per time

Anti interference: Input and output adopt optoelectronic isolation, with strong anti-interference ability
Stability: Equipped with a watchdog circuit and automatic reset function, ensuring stable operation of the system

Storage function: FLASH storage capacity: 4M bits (stored once every hour, can store for 1.6 years), can also be expanded to 32Mbit. It can also expand one USB storage interface to achieve USB storage;

Functional requirements: Intelligent collection, forwarding, and storage, with automatic and manual testing capabilities.

Sensor channel: Analog/Counting channel: 16 channels, expandable with 16 digital I/O channels for various external expansion functions Analog A/D conversion accuracy: 12 bits, frequency is collected using a 16 bit high-speed counter, and the input signal frequency is up to 1MHz

Power supply display: Wide voltage input: 8V~40V

Environmental temperature: -30~85 ℃

Power consumption: The overall power consumption of the machine is not more than 2W

ID setting: Supports setting network ID numbers and specifying device network addresses;

Display format: 192 * 64 full dot matrix LCD display, capable of displaying 12 * 4 Chinese characters, with a clear and beautiful overall interface; Expandable LED display screen for rich display; Simultaneously supporting real-time clock and time calibration functions

Data storage: Battery powered data protection is used in case of power failure, and the set parameters and historical data can be saved in case of power failure

Communication function: Equipped with three RS232/RS485/USB communication interfaces, capable of RS232/RS485/USB communication; And can expand one CAN bus communication interface;

Remote upgrade: supports remote application program updates: the acquisition instrument program can be changed and upgraded without returning to the factory. Remote program updates can be performed on the acquisition instrument through computer software, supporting on-site and remote programming operations for device parameter settings or reading

Communication protocol: Supports TCP/UDP communication mode, standard MODBUS protocol, dual protocol switching function, convenient for users to implement secondary programming of upper computer software.

Control function:

1. Intelligent multi-channel relay contact output;

2. Supports 16 sensor connections and 16 software configurable relay output interfaces, capable of controlling multiple backend devices. The core component adopts a high-performance industrial microprocessor as the main control CPU, with built-in large capacity data storage. Portable shockproof structure, designed according to industrial control standards, suitable for use in harsh environments;

3. Soil temperature, humidity, conductivity

Soil temperature:

Range: -40~80 ℃; Resolution: 0.1 ℃; Accuracy: ± 0.5 ℃

Soil moisture:

Range: 0-100% RH; Resolution: 0.1% RH; Accuracy: 5%

Soil conductivity:

Range: 0-10000 US/cm

Resolution: Within 0-10000 US/cm, 1 US/cm

Accuracy: ± 5% within the range of 0-10000 US/cm

Conductivity temperature compensation, built-in temperature compensation sensor, compensation range 0-50 ℃

Supply voltage: DC5V-24V

Signal output: RS485, Modbus protocol

Measurement principle:

Soil moisture FDR method, soil conductivity AC bridge method

Protection level: IP68 submerged in water for long-term use

Operating environment: -40~85 ℃

Probe material: anti-corrosion special electrode

Sealing material: Black flame retardant epoxy resin

Installation method: fully embedded or probe fully inserted into the measured medium

Default cable length: 5 meters, cable length can be customized according to requirements

Connection method: Pre installed cold pressed terminal

Dimensions: 45 * 15 * 135mm

Electrode length: 50mm

4 Soil tension meter

Working power supply: 3.5-24VDC

Output signal: Modbus

Response time: 200ms

Measurement accuracy: ± 0.5kpa

Resolution: ± 0.5kpa

Working current: 6mA

Working temperature: 0~60 ℃

Monitoring length: 60cm

Measurement range: -100kpa

Measurement medium: Organic matter in various soils and soilless cultivation

5. Rainfall sensor

承水口径： Ф200 ± 0.6mm

Measurement range: 0-4mm/min (precipitation intensity)

Resolution: 0.2mm (6.28ml)

Accuracy: ± 4% (indoor static test, rain intensity of 2mm/min)

Power supply mode: DC 5V

Output form: switch signal: reed switch on/off

Instrument cable length: Standard configuration: 5 meters

Working temperature: 0-50 ℃

Storage temperature: -10 ℃ to 50 ℃