HOBOnet Multi-Depth Soil Moisture Sensor

Data Loggers

HOBOnet Multi-Depth Soil Moisture Sensor

  • Vendor:Onset

Availability: Available Item
Qty Price
Buy 1 $1,317.00 ea
Buy 10 $1,251.15 ea

A complete system requires at least one HOBO RX3000 Remote Monitoring Station, a HOBOnet Wireless Manager (RXMOD-RXW-xxx), and a HOBOnet Wireless Sensor, OR one HOBO MicroRX Station (which has an integrated HOBOnet Wireless Manager) and a HOBOnet Wireless Sensor. HOBOnet Wireless Repeaters (RXW-RPTR-xxx or RXW-RPTR-B-xxx) can be added to extend the range.


The HOBOnet Multi-Depth Soil Moisture Sensor is a wireless sensor that works with the HOBOnet system to measure soil moisture and soil temperature at multiple depths with a single probe, for fast and easy installation. This durable sensor is available in three probe lengths for measurements from 45 cm (18 in) to 90 cm (35 in) deep.

Featuring GroPoint’s TDT5 technology with patented antenna design, these sensors measure soil moisture along the entire length of each probe segment, resulting in the largest volume of influence per measurement section. A high frequency of pulses per measurement provides precise and consistent soil moisture data.

We recommend using the optional pilot rod and slide hammer for quick and easy installation. Onset offers two options for the pilot rod, the PILOT-ROD4 (28”) for use with the three- and four-segment sensors (RXW-GP3 and RXW-GP4), and the PILOT-ROD6 (40”) for use with the six-segment sensor (RXW-GP6).

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. Sensors are easily linked to the network, and data can be accessed through HOBOlink®, Onset's innovative cloud-based software platform.

Highlighted Features

Sensor Features
  • Available in three probe lengths: 45 cm (18 in), 60 cm (24 in), and 90 cm (35 in)
  • Soil moisture measurements over entire probe segment lengths
  • Soil temperature measurements at multiple points
  • Largest volume of influence per measurement (2 L volume of influence per 15 cm segment)
  • Advanced filtering of 400,000 pulses per measurement eliminates outlying readings and provides precise, repeatable soil moisture data
  • Polycarbonate housing and epoxy-sealed circuit board protect vital components during installation and throughout deployment
  • Easy installation with minimal soil disturbance, and no digging required when using the optional pilot rod and slide hammer
Wireless Features
  • 900 MHz wireless mesh self-healing technology
  • 450 to 600 meter (1,500 to 2,000 feet) wireless range and up to five hops
  • Up to 50 wireless sensors or 336 data channels per one HOBO RX station
  • Simple button-push to join the HOBOnet wireless network
  • Onboard memory to ensure no data loss
  • Powered by rechargeable AA batteries and built-in solar panel

In what environment does this data logger operate?

This data logger operates in an outdoor environment.

What measurements does this data logger support?

The RXW-GPx-xxx sensor supports the following measurements: Soil Moisture and Soil Temperature

±0.5°C (0.9°F)
Soil Moisture: Volumetric Water Content (VWC)
Measurement Range In soil: 0 to 0.550 m³/m³ (volumetric water content)
Accuracy ±0.02 m³/m³ (±2%) in most soils typical from 0° to 50°C (32° to 122°F)*
Resolution 0.001 m³/m³
Measurement Range -20° to 70°C (-4° to 158°F)
0.1°C (0.18°F)
Depths Measured (see below)
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-GP3-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
Battery Type/Power Source Two AA 1.2V rechargeable NiMH batteries, powered by built-in solar panel or two AA 1.5 V non-rechargeable 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 Mounting and Positioning the Mote), operation outside this range will reduce the battery service life
With non-rechargeable lithium batteries:
RXW-GP3-xxx: 1 year with a 10-minute logging interval
RXW-GP4-xxx: 1 year with a 15-minute logging interval
RXW-GP6-xxx: 7 months with a 15-minute logging interval
Memory 16MB
Dimensions RXW-GP3-xxx sensor length: 53.2 cm (20.9 inches)
RXW-GP4-xxx sensor length: 68.2 cm (26.9 inches)
RXW-GP6-xxx sensor length: 98.2 cm (38.7 inches)
Sensor diameter: 3 cm (1.2 inches)
Cable length: 3 m (9.8 ft)
Mote: 16.2 x 8.59 x 4.14 cm (6.38 x 3.38 x 1.63 inches)
Weight RXW-GP3-xxx sensor: 351 g (12.4 oz)
RXW-GP4-xxx sensor: 408 g (14.4 oz)
RXW-GP6-xxx sensor: 526 g (18.6 oz)
Cable: 190 g (6.7 oz)
Mote: 223 g (7.87 oz)
Materials Sensor: Polycarbonate housing encasing epoxy sealed circuit board
Cable: Polyurethane
Mote: PCPBT, silicone rubber seal
Environmental Rating Mote: IP67, NEMA 6
Compliance Marks* Mote: IP67, NEMA 6
*Soil-specific calibration requires user post-processing in a spreadsheet program such as Microsoft® Excel® or a utility and connector as recommend by RioT Technology Corp., manufacturer of GroPoint sensors. Refer to Performing a Soil-Specific Calibration in the manual for details.