HOBOnet Multi-Depth Soil Moisture Sensor

SKU: RXW-GPx-921

Overview

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.

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.

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.

Wireless Features

  • 921 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 per 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 operate?

This operates in an outdoor environment.

What measurements does this support?

The supports the following measurements: Soil Moisture and Soil Temperature

What’s in the Box?

  • HOBOnet Multi-Depth Soil Moisture Sensor
  • Two AA 1.2V rechargeable NiMH batteries
  • Cable ties
  • Screws

Important Info:

A complete system requires at least one HOBO RX Remote Monitoring Station, a HOBOnet Wireless Manager (RXMOD-RXW-921), and a HOBOnet Wireless Sensor. HOBOnet Wireless Repeaters (RX-RPTR-921) can be added to extend the range.

Wireless Mote

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Operating Temperature Range

-25° to 60°C with rechargeable batteries
-40 to 70°C 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

921 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 RX 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

Battery Life

With NiMH batteries: Typical 3–5 years when operated in the temperature range -20° to 40°C 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

Dimension

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

Cable: 190 g (6.7 oz)
Mote: 223 g (7.87 oz)

Material

Sensor: Polycarbonate housing encasing epoxy sealed circuit board
Cable: Polyurethane
Mote: PCPBT, silicone rubber seal

Environmental Rating

Mote: IP67, NEMA 6

Soil Moisture: Volumetric Water Content (VWC) Sensor

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Measurement Range

0.000 to 1.000 m³/m³ in most soils

Temperature Sensor

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Measurement

-20° to 70°C

Accuracy

±0.5°C

Resolution

0.1°C

RXW-GP3-921

45 cm (18 inches) total; three soil moisture zones, six temperature depths

RXW-GP4-921

60 cm (24 inches) total; four soil moisture zones, seven temperature depths

RXW-GP5-921

90 cm (35 inches) total; six soil moisture zones, eleven temperature depths

Data Sheet

Download

Manual

Download

Quick Start Guide

Download