Product Overview
The OHTS1022 is a composite sensor integrating soil volumetric water content (VWC) and soil temperature measurements designed for long-term buried soil monitoring applications. Moisture measurement is based on the Frequency Domain Reflectometry (FDR) principle, achieving high-precision volumetric water content measurement by detecting changes in soil dielectric constant. Temperature measurement utilizes a Class A PT1000 precision platinum resistance temperature detector (RTD), integrating signal conditioning, temperature compensation, and data processing modules.
The sensor features an integrated sealed structural design with IP68 ingress protection rating, enabling direct burial in soil for long-term operation or immersion in water. It supports multiple standard industrial output interfaces, including voltage signals (0 ~ 2V, 0 ~ 5V, 0 ~ 10V), current signals (4 ~ 20mA), and RS485 digital interface (Modbus-RTU protocol), ensuring compatibility with various data acquisition terminals and PLC systems.
Features
- Integrated Design: Combined soil moisture and temperature sensing elements in a unified package, reducing field installation complexity and providing comprehensive soil environment data.
- FDR Measurement Principle: Utilizes Frequency Domain Reflectometry technology for volumetric water content measurement, detecting soil dielectric constant changes with high precision.
- PT1000 Temperature Sensor: Employs Class A platinum resistance temperature detector (RTD) with integrated signal conditioning and temperature compensation for accurate temperature readings.
- IP68 Protection Rating: Features epoxy resin sealing and robust construction suitable for long-term burial in soil or immersion in water without performance degradation.
- Multiple Output Interfaces: Supports 0 ~ 2V, 0 ~ 5V, 0 ~ 10V voltage outputs, 4 ~ 20mA current output, and RS485 digital communication with Modbus-RTU protocol for flexible system integration.
- Fast Response Characteristics: Response time less than 1 second and settling time less than 1 second enable real-time monitoring applications.
- Durable Construction: 316L stainless steel probes combined with ABS engineering plastic housing provide excellent corrosion resistance and mechanical durability.
- Interchangeable Design: Standardized probe design supports interchangeability for easy maintenance and replacement in the field.
Applications
The OHTS1022 is designed for comprehensive soil monitoring across multiple sectors:
- Water-saving Agricultural Irrigation: Precision soil moisture monitoring to optimize irrigation scheduling and reduce water consumption in agricultural systems.
- Meteorological Observation Stations: Soil environmental parameter acquisition for weather stations and climate monitoring networks.
- Ecological Environment Monitoring: Long-term deployment in ecological monitoring networks for continuous soil condition assessment.
- Greenhouse Management: Crop root zone environment regulation in controlled greenhouse cultivation systems.
- Grassland and Pasture Management: Soil water management solutions for grasslands, pastures, and rangeland ecosystems.
- Field Surveying: Rapid soil measurement and surveying applications requiring portable, reliable soil sensing.
- Plant Cultivation Research: Substrate monitoring for scientific plant cultivation experiments and botanical studies.
- Soil Science Research: Experimental observation and data collection for academic soil science research programs.
Technical Specifications
| Parameter | Specification | Remarks |
|---|---|---|
| Measured Parameters | Soil Volumetric Water Content; Soil Temperature | - |
| Measurement Units | m³/m³ (%); °C | - |
| Moisture Range | 0 ~ 100% (m³/m³) | Optional 30%, 50% range or custom ranges available |
| Temperature Range | -30 ~ 70°C | Customizable to 0 ~ 50°C or other ranges |
| Moisture Accuracy | ±2% (m³/m³) | Within 0 ~ 50% (m³/m³) range |
| Temperature Accuracy | ±0.2°C | - |
| Operating Temperature Range | -30 ~ 70°C | - |
| Output Signal Type A | 0 ~ 2V / 0 ~ 5V / 0 ~ 10V | Select one of three |
| Output Signal Type B | 4 ~ 20mA | Current loop output |
| Output Signal Type C | RS485 | Standard Modbus-RTU protocol, default address 01 |
| Supply Voltage (Voltage/RS485 Output) | 5 ~ 24V DC | - |
| Supply Voltage (Current/High Voltage Output) | 12 ~ 24V DC | Applicable for 0 ~ 5V, 0 ~ 10V, 4 ~ 20mA |
| Settling Time | <1s | - |
| Response Time | <1s | - |
| Measurement Zone | Cylinder with diameter 7cm and height 7cm | Centered on the central probe |
Current Signal Impedance Requirements:
| Supply Voltage | 9V | 12V | 20V | 24V |
|---|---|---|---|---|
| Maximum Impedance | 125Ω | 250Ω | 500Ω | >500Ω |
Physical Specifications
| Parameter | Specification |
|---|---|
| Probe Length | 55mm |
| Probe Diameter | φ3mm |
| Probe Material | 316L Stainless Steel |
| Housing Material | ABS Engineering Plastic |
| Sealing Material | Epoxy Resin |
| Protection Rating | IP68 |
| Cable Length | Standard 2m (Customizable, maximum 1200m) |
FAQ
Q: What measurement principles does the OHTS1022 use?
A: The OHTS1022 uses Frequency Domain Reflectometry (FDR) principle for soil volumetric water content measurement by detecting changes in soil dielectric constant, and Class A PT1000 platinum resistance temperature detector (RTD) for temperature measurement.
Q: What protection rating does the OHTS1022 have?
A: The sensor has IP68 ingress protection rating with an integrated sealed structural design using epoxy resin sealing, enabling direct burial in soil for long-term operation or immersion in water.
Q: What output signals are supported by the OHTS1022?
A: The sensor supports voltage signals (0 ~ 2V, 0 ~ 5V, 0 ~ 10V), current signals (4 ~ 20mA), and RS485 digital interface with Modbus-RTU protocol, ensuring compatibility with various data acquisition terminals and PLC systems.
Q: What are the installation precautions for the OHTS1022?
A: Strictly prohibit direct insertion of probes into stones, hard clods, or frozen soil to prevent probe bending or damage. When removing the sensor from soil, grip the sensor body and never pull the cable directly. Ensure full contact between the sensor probe and soil to minimize operational errors.
Q: What are the power supply requirements?
A: For voltage and RS485 output, the supply voltage is 5 ~ 24V DC. For current output and high voltage output (0 ~ 5V, 0 ~ 10V, 4 ~ 20mA), the supply voltage is 12 ~ 24V DC.