HOBOnet® Wireless Sensor Network
RXW TEROS-12 Soil Moisture EC Temp Sensor (RXW-T12-xxx) Manual
24747-A
This sensor measures soil moisture, temperature, and electrical conductivity (EC) in numerous
soil types, including high salinity and sandy soil. It is designed to work with the HOBOnet (HOBO
RX) Wireless Sensor Network in which data is transmitted wirelessly from the sensor mote
across the network to the station and then uploaded to HOBOlink® web-based software. With
HOBOlink, you can monitor sensor readings, view graphs, set up alarms, download data, and
more.
Specifications
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
Resolution
0.001 m³/m³
Dielectric Measurment
Frequency
70 MHz
Temperature**
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)
Resolution
0.1°C (0.18°F)
Bulk Electrical Conductivity (EC)
Measurement Range
0 to 20 dS/m (bulk)
Accuracy
±5% of r 0.01 dS/m from 0 to 10 dS/m
±8% 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
RXW Soil Moisture EC
Temp Sensor
Models:
•
RXW-T12-900 (US)
•
RXW-T12-868 (Europe)
•
RXW-T12-921 (Taiwan)
•
RXW-T12-922
(Australia/NZ)
Included Items:
•
Cable ties
•
Screws