Warden is an online TDR (Time Domain Reflectometry) soil moisture meter of moisture, temperature and electrical conductivity. Minimal footprint meter equipped with an internal data recorder and eight channels, which can be used in both the lab and the field. Tiny sensors follow true TDR principle, the upper frequency of the analyzing needle pulse is about 1.5 GHz. Special designed sensor body with ultimate low heat conductivity, avoid the parasite "thermal bridge" effects on distribution of soil moisture in the probe’s sensor vicinity. Warden is easy to connect with internet for cloud data storage, remote data access, configuration and synchronization of internal clock.
Technology
TDR（Time Domain Reflectometry)
Features
- Minimal footprint datalogger with up to 16 connection ability
- True TDR principle with 1.5GHz upper frequency
- Measurement of soil moisture, temperature and salinity
- No special maintenance means are required
- Ultra-low power consumption for both work mode sleep mode
Technical parameters
| Warden data logger | |
| Channels | 8 Channels, ability to connect up to 16 warden units |
| Calibration | Each TDR channel and TDR sensor can be calibrated separately |
| Power | 6 -15 V DC |
| Operating Temperature | -20 to 50℃ |
| TDR-001 Soil Moisture Sensor and TDR-002 Soil Moisture, Electrical Conductivity, Temperature sensor | |
| Accuracy | soil moisture ±2%，electrical conductivity±10 %, temperature 0.5℃ |
| Sensor | two 100 mm long parallel stainless steel rods having 2 mm diameter and separated by 16 mm |
| Region of Influence | a cylinder having approximated diameter of 5 cm and height of 11 cm |
| Sensor Support | a section of a PVC tube having 2 cm outer diameter and optional length (15cm-150cm or longer) dependent on the intended depth of the sensor installation |
| Cable Length | from1.5 to 9m from the sensor to the terminating connector |
| TDR-003 Laboratory Miniprobe for Soil Moisture and Salinity | |
| Installation Hole | metric thread diameter of 8mm, height of 3.3 mm |
| Sensor | two 53 mm long parallel stainless steel rods diameter of 0.8, separated by 5 mm |
| Sphere of Influence | a cylinder having diameter of about 5 mm and height of about 60 mm |
| Cable Length | 2 m from the sensor to the terminating connector (or multiplexer) |
| TDR-004 Laboratory Miniprobe for Soil Water Capillary Pressure | |
| Pressure Diaphragm | 15 mm long ceramic cup, 3 mm in diameter |
| Offset Drift | ± 20 mbar/month，relative error: ± 15 %, resolution: 1 mbar |
| Cable Length | 2m |
| Installation Hole | 8 mm diameter |
| TDR-005 Laboratory Probe for Soil Temperature | |
| Range | temperature between -20°C and +60°C |
| Resolution | 0.01°C |
| Absolute Error | not more than ±1°C or ±0.1°C if individually calibrated |
| Cable Length | 2m |
| Installation Hole | 8 mm diameter tapped with 8/1.5 mm thread |
| Soil column metal cylinder（for placing soil column samples and installing sensors） | |
| Specifications | Wall thickness 2.75mm, height 100mm, inner diameter 55mm |
| Features | The cylinder wall is provided with sensor mounting holes for installing LP/MS and LP/P sensors. Install the hole spiral distribution to minimize the impact between sensors |
Manufacturer：PRI-ECO