Overview
Provides accurate leaf wetness data for a variety of growing and research applications. This preconfigured, ready-to deploy sensor requires no painting or coating, uses a capacitive grid that is less sensitive to surface residues than resistive grid-based sensors, and comes preconditioned for long-term stability and consistent measurements between sensors.
HOBOnet wireless sensors communicate data directly to the HOBO RX3000 or the HOBO MicroRX station or pass data through other wireless sensors back to the central station. Data is accessed through HOBOlink, Onset's innovative cloud software platform.
Features
Sensor Features
Does not require any painting or coating
Preconditioned for consistent measurements
3-meter cable and mounting bracket included
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 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
Specifications
Sensor
Measuring range
0 (dry) to 100% (wet)
Sensor type
Capacitive grid
Interchangeability between sensors (in the range 10 to 90% wet)
±10%
Repeatability
±5%; See Note 1
Resolution
0.59%
Stability (drift)
<±5% per year
under typical growing conditions
Lifespan
3 years under typical growing conditions
Wireless Mote
Operating Temperature Range
-25°C to 60°C (-13°F to 140°F) with rechargeable batteries
-40°C to 70°C (-40°F to 158°F) with lithium batteries
Radio Power
12.6 mW (+11 dBm) non-adjustable
Transmission Range
Reliable line-of-sight connection from 457.2 m (1500 ft) at 1.8 m (6 ft) height
Reliable line-of-sight connection from 609.6 m (2000 ft) at 3 m (10 ft) height
Wireless Data Standard
IEEE 802.15.4
Radio Operating Frequencies
RXW-LWA-900: 904-924 MHz
RXW-LWA-868: 866.5 MHz
RXW-LWA-922: 916-924 MHz
RXW-LWA-921: 921 MHz
Modulation Used
OQPSK
Quadrature Phase Shift Keying with offset
Data Rate
Up to 250 kbps, not adjustable
Duty Cycle
<1%
Maximum Number of Motes
Up to 50 wireless sensors or 336 data channels per one HOBO RX station
Recording Rate
1 minute to 18 hours
Number of Data Channels
2
Battery Type/Power Supply
Two 1.2V AA NiMH rechargeable batteries V powered by integrated solar panel or two 1.5V AA lithium batteries for operating conditions of -40 to 70°C (-40 to 158°F)
Battery Life
With NiMH Batteries: Typically 3 to 5 years when used in a temperature range of -20° to 40°C (-4°F to 104°F) and facing the sun (see Deployment and Mounting); Operation outside this range will reduce battery life
With lithium batteries: 1 year, typical use
Memory
16 MB
Dimensions
Sensor grid: 4.7 x 5.1 cm (1.8 in x 2.0 in)
Sensor housing: 12.2 x 1.8 cm (4.8 in x 0.7 in)
Mounting bracket: 20 x 3 x 0.5 cm (8 x 1.3 x 0.2 in)
Cable length: 2 m (6.56 ft)
Mote: 16.2 x 8.59 x 4.14 cm (6.38 x 3.38 x 1.63 in)
Weight
Sensor and cable: 127 g (4.5 oz); with bracket: 290 g (10.2 oz)
Mote: 223 g (7.87 oz)
Materials
Sensor: PVC housing, epoxy potting compound, nylon grommet, FR-4 circuit board, PVC cable jacket
Bracket: PVC mounting bracket, UV-resistant nylon cable ties, zinc dichromate-coated steel U-bolts
Mote: PCPBT, silicone rubber seal
Environmental rating
Sensor and cable: Weatherproof
Mote: IP67, NEMA 6
