| Soil Moisture: Volumetric Water Content (VWC) |
| Measurement Range* |
0.00 to 0.70 mł/mł in mineral soils |
| Accuracy |
ą0.030 mł/mł (ą3%) typical from 0 to 50°C (32 to 122°F); ą0.020 mł/mł (ą2%) with soil specific calibration |
| Resolution |
0.001 mł/mł |
| Dielectric Measurement Frequency |
70 MHz |
| Temperature** |
| Measurement Range |
-40 to 60°C (-40 to 140°F) |
| Accuracy |
ą0.5°C (0.9°F) from -40 to 0°C (-40 to 32°F) |
| ą0.3°C (0.54°F) from 0 to 60°C (32 to 140°F) |
| Resolution |
0.1°C (0.18°F) |
| Bulk Electrical Conductivity (EC) |
| Measurement Range |
0 to 20 dS/m (bulk) |
| Accuracy |
ą5% of reading + 0.01 dS/m from 0 to 10 dS/m |
| ą8% of reading from 10 to 20 dS/m |
| Resolution |
0.001 dS/m |
| Wireless Mote |
| 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 |
| Duty Cycle |
<1% |
| Maximum Number of Motes |
50 motes per one HOBOnet Wireless Sensor Network |
| Battery Type/Power Source |
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 |
| Memory |
16 MB |
| 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 |
| Compliance Marks |
Federal Communication Commission RXW-T12-900
European Union Compliance RXW-T12-868
Taiwan Compliance RXW-T12-921
Australia and New Zealand Complicance RXW-T12-922 |
* 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. |