| Water Potential |
| Measurement Range |
-2,000 to -9 kPa in soils up to 10 dS/m |
| Accuracy* |
ą10% of reading + 2 kPa from -100 to -9 kPa |
| Resolution |
0.1 kPa |
| Dielectric Measurement Frequency |
70 MHz |
| Temperature |
| Measurement Range |
-40 to 60°C (-40 to 140°F) |
| Accuracy |
ą1°C (1.8°F) |
| Resolution |
0.1°C (0.18°F) |
| 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-T21-900: 904924 MHz
RXW-T21-868: 866.5 MHz
RXW-T21-921: 921 MHz
RXW-T21-922: 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 35 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 |
| Memory |
16 MB |
| Dimensions |
Sensor: 9.6 x 3.5 x 1.5 cm (3.8 x 1.4 x 0.6 inches)
Sensor diameter: 3.2 cm (1.3 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-T21-xxx sensor and cable: 103 g (3.65 oz)
Mote: 223 g (7.87 oz) |
| Materials |
Sensor: Vinyl body with polyurethane resin, stainless steel and ceramic sensor head
Cable: PVC, UV resistant and rodent repellent
Mote: PCPBT, silicone rubber seal |
| Environmental Rating |
Mote: IP67, NEMA 6 |
| Compliance Marks |
Federal Communication Commission RXW-T11-900
European Union Compliance RXW-T11-868
Taiwan Compliance RXW-T11-921
Australia and New Zealand Complicance RXW-T11-922 |
* The sensor is not well calibrated beyond -100 kPa. For more information on using the sensor beyond this range, see Sensor Accuracy and Calibration.
** Temperature measurement, for applicable sensors, may not be accurate if sensor is not fully immersed in medium of interest, due to longer equilibration time. |