Soil Moisture Monitoring is a tube-style sensor based on the dielectric constant principle, capable of simultaneously measuring temperature, moisture, and electrical conductivity across five soil depth layers. Utilizing the RS-485 Modbus RTU communication protocol and consuming only 0.26W of power, the device is suitable for long-term monitoring in agricultural applications such as smart greenhouses, orchards, and irrigation systems.
Designed specifically for agricultural soil monitoring, Soil Moisture Monitoring measures three key parameters across the soil profile: temperature, moisture, and electrical conductivity. It employs a mathematical model based on soil dielectric constant principles and uses helical electrodes to acquire volumetric water content data. With a 60-second startup time, a power supply of 12V DC (22mA), and a total power consumption of just 0.26W, it is ideal for long-term, unattended field monitoring. The device supports the RS-485 Modbus RTU protocol and measures parameters across five layers by default; however, the number of monitoring layers is customizable, ranging from a minimum of three to a maximum of ten.
Regarding measurement accuracy, the soil temperature range is -30 to 70°C, with an accuracy of ±0.3°C (within the -10 to 70°C range) and a resolution of 0.01°C. The soil moisture measurement range is 0 to 100%, with an accuracy of ±3% in loam; however, calibration for specific soil types may be required for soils with high organic matter or clay content due to dielectric relaxation characteristics. The soil electrical conductivity range is 0 to 20,000 µS/cm, with an accuracy of ±3% (within the 0 to 10,000 µS/cm range) and ±5% across the full scale, featuring a resolution of 1 µS/cm.
The Soil Moisture Monitoring housing is constructed from imported PC material, offering high strength and corrosion resistance. With an IP67 waterproof rating, it is built to withstand long-term outdoor monitoring environments. The sensor features a helical electrode design that improves contact with the soil, effectively eliminating measurement errors caused by air gaps. Each sensor layer independently measures temperature, humidity, and electrical conductivity; by measuring the average humidity across a specific area, the system overcomes the limitations inherent in single-point measurements. A single tubular sensor can simultaneously measure soil parameters at multiple depths, with the monitoring depth customizable to specific requirements.
The Soil Moisture Monitoring is primarily designed for use by agricultural bureaus, universities, research institutes, water conservancy and environmental protection agencies, as well as various enterprises and institutions. In practical applications, it is widely utilized in agricultural engineering sectors such as smart greenhouses, smart orchards, and smart irrigation systems. Installation employs a borehole method: a soil auger is used to drill a hole at the designated location; a mixture of the excavated soil and cement slurry is poured into the hole; and the sensor is then slowly inserted, rotated, and pressed down to the correct depth. When multiple sensors are deployed simultaneously, they must be spaced at least 3 meters apart, and the installation sites must be free from electromagnetic cables or sources of strong magnetic interference within a 3-meter radius. The device supports a hybrid power system combining solar power and battery storage, ensuring continuous operation in field environments without an external power supply.
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