Rapid determination of soil moisture is required in the fields of soil and water conservation monitoring, soil hydrological monitoring, smart soil monitoring system ,precision agricultural production and irrigation. The determination methods include drying method, ray method, dielectric property method, nuclear magnetic resonance method, separation tracer method and remote sensing method. Among them, the dielectric characteristic method is an indirect measurement based on the dielectric properties of soil, which can realize the rapid and non-destructive measurement of soil moisture. Specifically, the smart soil sensor can be divided into the time domain reflection TDR principle and the frequency reflection FDR principle.MTQ-11SM series soil moisture sensor irrigation is a dielectric sensor based on the principle of frequency reflection FDR. It can measure the change of capacitance on the sensor at 100MHz frequency to measure the dielectric constant of the inserting medium. Because the dielectric constant of water is very high (80), the soil is (3-10). Therefore, when the moisture content in soil changes, the dielectric constant of soil also changes considerably. This series of soil moisture sensor circuit reduces the influence of temperature change on the measurement. Digital technology and durable materials are adopted, which have high measurement accuracy and low cost. The sensor can continuously monitor the water content in many sample plots and different soil depths for a long time.
● Measuring soil volumetric water content in the 200 cm capacity range around the probe
● Design of 100 MHz circuit for soil moisture sensor
● Low sensitivity in high salinity and cohesive soils
● High protection (IP68) for long-term burial in soil
● Wide voltage supply, non-linear correction, high accuracy and consistency
● Small size, light weight and easy installation
● Strong anti-lightning, frequency-cut interference design and anti-jamming capability
● Reverse and Overvoltage Protection, Current Limiting Protection (Current Output)
| Parameters | Description |
| Sensor principle | Frequency Domain Reflection FDR |
| Measurement parameters | Soil volume water content |
| Measuring range | Saturated water content |
| Moisture range | 0-60%m³/m³ |
| Temperature range | 0-50℃ |
| Output signal | 4~20mA, RS485 (Modbus-RTU protocol), 0~1VDC, |
| 0~2.5VDC | |
| Supply voltage | 5-24VDC、12-36VDC |
| Moisture accuracy | 3% (after the rate is determined) |
| Temperature accuracy | ±0.5℃ |
| resolution | 0.001 |
| Response time | ＜500ms |
| Operating environment | Outdoor, the suitable ambient temperature is 0-45°C |
| Operating current | 45-50mA, with temperature<80mA |
| Cable length | 5 meters standard (or customized) |
| Housing material | ABS engineering plastics |
| Probe material | 316 stainless steel |
| gross weight | 500g |
| Degree of protection | IP68 |