The HOBOnet T12 is a wireless sensor that works with the HOBOnet system to not only provide advanced soil moisture (volumetric water content) measurements with better accuracy and precision but also measure soil temperature and electrical conductivity. 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 probe tips make installation easy, even in hard soil, and a large volume of influence provides more accurate results. Featuring the METER TEROS 12 soil moisture and temperature sensor, the HOBOnet T12 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 recommend 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), soil temperature, and electrical conductivity 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-T12-900 sensor supports the following measurements: Electrical Conductivity (soil), 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||±0.5°C (0.9°F) from -40 to 0°C (-40 to 32°F)
±0.3°C (0.54°F) from 0 to 60°C (32 to 140°F)
|Bulk Electrical Conductivity (EC)|
|Measurement Range||0 to 20 dS/m (bulk)|
|Accuracy||±5% of reading + 0.01 dS/m from 0 to 10 dS/m
±8% of reading from 10 to 20 dS/m
|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-T12-900: 904–924 MHz
RXW-T12-868: 866.5 MHz
RXW-T12-921: 921 MHz
RXW-T12-922: 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 Deployment and Mounting), 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-T12-xxx sensor and cable: 245 grams (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.