HOBOnet® Wireless Sensor Network
RXW Multi-Depth Soil Moisture Sensor (RXW-GPx-xxx) Manual
25115-A
This sensor measures soil moisture and temperature over multiple zones with a single probe
using GroPoint™ TDT technology. 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
0.000 to 1.000 m³/m³ in most soils
Accuracy
±0.02 m³/m³ (±2%) in most soils typical from 0° to 50°C (32° to 122°F)*
Resolution
0.001 m³/m³
Temperature
Measurement Range
-20° to 70°C (-4° to 158°F)
Accuracy
±0.5°C (0.9°F)
Resolution
0.1°C (0.18°F)
Depths Measured (see diagram on page 3)
RXW-GP3-xxx
45 cm (18 inches) total; three soil moisture zones, six temperature depths
RXW-GP4-xxx
60 cm (24 inches) total; four soil moisture zones, seven temperature depths
RXW-GP6-xxx
90 cm (35 inches) total; six soil moisture zones, eleven temperature depths
Wireless Mote
Operating Temperature
Range
Sensor: -20° to 70°C (-4° to 158°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-GPx-900: 904–924 MHz
RXW-GPx-868: 866.5 MHz
RXW-GPx-921: 921 MHz
RXW-GPx-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
Up to 50 wireless sensors or 336 data channels per one HOBO RX station
Logging Rate
Maximum logging interval: 18 hours
Recommended minimum logging interval:
Using Solar Power with
Rechargeable Batteries
Using Non-Rechargeable
Lithium Batteries
RXW-GP3-xxx:
5 minutes year round
10 minutes
RXW-GP4-xxx:
5 minutes summer,
10 minutes winter
15 minutes
RXW-GP6-xxx:
5 minutes summer,
10 minutes winter
15 minutes
See Battery Life specification for more details.
Number of Data Channels
RXW-GP3-xxx: 10
RXW-GP4-xxx: 12
RXW-GP6-xxx: 18
RXW Multi-Depth Soil
Moisture Sensor
Models:
•
RXW-GP3-900 (US)
RXW-GP3-868 (Europe)
RXW-GP3-921 (Taiwan)
RXW-GP3-922 (Australia/NZ)
•
RXW-GP4-900 (US)
RXW-GP4-868 (Europe)
RXW-GP4-921 (Taiwan)
RXW-GP4-922(Australia/NZ)
•
RXW-GP6-900 (US)
RXW-GP6-868 (Europe)
RXW-GP6-921 (Taiwan)
RXW-GP6-922 (Australia/NZ)
Included Items:
•
Cable ties
•
Screws
