Hobo S-LWA-M003 Manual Download Page 1

Leaf Wetness Smart Sensor (S-LWA-M003) Manual 

9826-F MAN-S-LWA 

The leaf wetness smart sensor is designed to work with HOBO® stations with its plug-in 
modular connector. All calibration parameters are stored inside the smart sensor, which 
automatically communicates configuration information to the station without the need for any 
programming, calibration, or extensive setup. Unlike other leaf wetness sensors, the HOBO leaf 
wetness smart sensor does not require any painting or coating—it is ready to use. 

Specifications 

Measurement Range 

0 (dry) to 100% (wet) 

Sensor Type 

Capacitive grid 

Interchangeability Between 
Sensors (Over the Range  
10–90% Wet) 

±10% 

Repeatability 

±5%; see Note 1 

Resolution 

0.59% 

Stability (Drift) 

< ±5% per year (in typical growth conditions) 

Service Life 

3 years in typical growth conditions 

Operating Temperature Range 

-40°C to 70°C (-40°F to 158°F) 

Environmental Rating 

Weatherproof 

Sensor Construction Materials 

PVC housing, epoxy potting compound, nylon grommet, FR-4 circuit 
board, PVC cable jacket 

Bracket Materials 

PVC mounting bracket, UV-stable nylon cable ties, zinc dichromate 
plated steel U-bolts 

Bits per Sample 

Number of Data Channels* 

Measurement Averaging Option 

No 

Dimensions 

Sensor grid: 4.7 cm x 5.1 cm (1.8 in x 2.0 in) 
Housing: 12.2 cm length x 1.8 cm diameter (4.8 in x 0.7 in) 
Mounting bracket: 20 cm x 3 cm x 0.5 cm (8 in x 1.3 in x 0.2 in) 

Weight (Sensor and Cable) 

127 g (4.5 oz) 

Weight (Including Mounting 
Bracket) 

290 g (10.2 oz) 

Cable Length Available 

3.0 m (9.8 ft) 

Length of Smart Sensor 
Network Cable* 

3.0 m (9.8 ft) 

 

The CE Marking identifies this product as complying with all relevant 
directives in the European Union (EU). 

*  A single station can accommodate 15 data channels and up to 100 m (328 ft) of smart sensor cable (the digital 

communications portion of the sensor cables). 

Note 1  Given the nature of the sensor design and sensor operating frequency, the system has inherent susceptibilities to 

Radio Frequency signals. The repeatability specification when subjected to certain RFI environments, such as 
those outlined in IEC 61000-4-3 and IEC 61000-4-6, may be significantly reduced. 

The system level repeatability will be particularly affected when placed in an electric field of 3 V/m or greater in 
the 150 KHz to 1000 MHz range. RFI mitigation practices and physical deployment changes may reduce the 
system susceptibility. If deployments are planned in high RFI energy environments, Onset recommends on-site 
testing to determine system level repeatability. 

 

 

Leaf Wetness Smart 
Sensor 

S-LWA-M003 

Items Included: 

 

Mounting bracket 

 

U-bolt 

 

Tie wraps 

 

 

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