A complete system requires at least one HOBO RX3000 Remote Monitoring Station, a HOBOnet Wireless Manager (RXMOD-RXW-xxx), and a HOBOnet Wireless Sensor, OR one HOBO MicroRX station (which has an integrated HOBOnet Wireless Manager) and a HOBOnet Wireless Sensor. HOBOnet Wireless Repeaters (RXW-RPTR-900) can be added to extend the range.
The HOBOnet T11 is a wireless sensor that works with the HOBOnet system to not only measure soil moisture (volumetric water content) with better accuracy and precision but also provide soil temperature measurements. Designed to withstand harsh environmental conditions, these durable sensors last up to 10 years, so you can leave them in the field for extended periods of time. Sharpened stainless-steel probes make installation easy, even in hard soil, and a large volume of influence provides better results and a more accurate view of soil moisture. Featuring the METER TEROS 11 soil moisture and temperature sensor, the HOBOnet T11 is backed by over 20 years of soil moisture research and leverages METER’s trademark 70MHz frequency capacitance technology, minimizing salinity and textural effects.
The HOBOnet system is a cost-effective and scalable wireless sensor network for web-enabled monitoring of field conditions for applications such as crop management, research, and greenhouse operations. And because it’s wireless, you can deploy a network of sensors to easily monitor multiple points with a single system, while avoiding the risk of long cables that can interfere with field operations and are potentially vulnerable to nearby lightning strikes.
Sensors are easily linked to the network, and data can be accessed through HOBOlink®, Onset's innovative cloud-based software platform.
We suggest using the TEROS Verification Clip, available from the Compatible Items tab. TEROS Verification Clip provides a convenient way to confirm the operation and soil moisture accuracy of the HOBOnet T11 and T12 sensors. Attaching this clip to a TEROS sensor provides a known soil moisture level for verifying measurement accuracy without needing to go through the work of testing the sensor in actual soils, which would normally require weighing soil samples and drying them in an oven.
- Soil moisture (volumetric water content) and soil temperature measurements with one device
- Sensor lasts up to 10 years in the field
- Largest volume of influence (1010 mL) relative to sensor size, resulting in more accurate soil moisture measurements
- Easy installation with sharpened stainless-steel probes that are more resistant to damage/deterioration
- Less sensor-to-sensor variability
In what environment does this sensor operate?
This sensor operates in an outdoor environment.
What measurements does this sensor support?
The RXW-T11-xxx sensor supports the following measurements: Soil Moisture and Soil Temperature
|Soil Moisture: Volumetric Water Content (VWC)|
|Measurement Range*||0.00 to 0.70 m³/m³ in mineral soils|
|Accuracy||±0.030 m³/m³ (±3%) typical from 0 to 50°C (32 to 122°F); ±0.020 m³/m³ (±2%) with soil specific calibration|
|Dielectric Measurement Frequency||70 MHz|
|Measurement Range||-40 to 60°C (-40 to 140°F)|
|Accuracy||±1.0°C (1.8°F) from -40 to 0°C (-40 to 32°F)
±0.5°C (0.9°F) from 0 to 60°C (32 to 140°F)
|Operating Temperature Range||Sensor: -40 to 60°C (-40 to 140°F)
Mote: -25° to 60°C (-13° to 140°F) with rechargeable batteries
-40 to 70°C (-40 to 158°F) with lithium batteries
|Radio Power||12.6 mW (+11 dBm) non-adjustable|
|Transmission Range||Reliable connection to 457.2 m (1,500 ft) line of sight at 1.8 m (6 ft) high
Reliable connection to 609.6 m (2,000 ft) line of sight at 3 m (10 ft) high
|Wireless Data Standard||IEEE 802.15.4|
|Radio Operating Frequencies||RXW-T11-900: 904–924 MHz
RXW-T11-868: 866.5 MHz
RXW-T11-921: 921 MHz
RXW-T11-922: 916–924 MHz
|Modulation Employed||OQPSK (Offset Quadrature Phase Shift Keying)|
|Data Rate||Up to 250 kbps, non-adjustable|
|Maximum Number of Motes||50 motes per one HOBOnet Wireless Sensor Network|
|Two AA 1.2V rechargeable NiMH batteries, powered by built-in solar panel or two AA 1.5 V lithium batteries for operating conditions of -40 to 70°C (-40 to 158°F)|
|Battery Life||With NiMH batteries: Typical 3–5 years when operated in the temperature range -20° to 40°C (-4°F to 104°F) and positioned toward the sun (see Mounting and Positioning the Mote), operation outside this range will reduce the battery service life
With lithium batteries: 1 year, typical use
|Dimensions||Sensor: 7.47 x 9.4 x 2.39 cm (2.94 x 3.7 x 0.94 inches)
Sensor needle length: 5.4 cm (2.13 inches)
Sensor needle diameter: 0.32 cm (0.13 inches)
Cable length: 5 m (16.4 ft)
Mote: 16.2 x 8.59 x 4.14 cm (6.38 x 3.38 x 1.63 inches)
|Weight||RXW-T11-xxx sensor and cable: 245 g (8.64 oz)
Mote: 223 g (7.87 oz)
|Materials||Sensor: ASA plastic body with polyurethane epoxy filling and stainless steel pins
Cable: PVC, UV resistant and rodent repellent
Mote: PCPBT, silicone rubber seal
|Environmental Rating||Mote: IP67, NEMA 6|
* The sensor data can be post-calibrated if necessary (e.g. the sensor is used in non-mineral soil types or higher than standard accuracy is required). Users can apply a calibration equation to the data exported from HOBOlink. The VWC range will depend on the calibration equation.
** Temperature measurement, for applicable sensors, may not be accurate if sensor is not fully immersed in medium of interest, due to longer equilibration time.
- cable ties