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Onset HOBO U20L Low-Cost Water Level Data Loggers. Available in 0 to 13ft, 0 to 30 ft and 0 to 100 ft Water Depth Ranges

HOBO U20L Low-Cost Water Level Data Logger

Onset Temperature and Water Level Data Loggers for Water Level Studies and Research

Part Number: U20L-01

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  • Recording Changing Water Level (Depth) and Temperature in Wet or Water Environments

  • -20°C to 50°C Temperature Measurement Range with ±0.44°C Accuracy

  • Factory-Replaceable 2/3 AA Lithium Battery with 5 Year Life (1 Minute Sampling Rate)

  • Stores up to 21,700 Measured Readings with Date/Time Stamp

  • 0 to 13 ft, 0 to 30 ft and 0 to 100 ft Water Level Ranges Available with ± 0.1% RF Accuracy

Requires HOBOware Pro Software (Version 3.2+) and an Optic USB Base Station (BASE-U-4) or Shuttle Data Transporter (U-DTW-1)

Special order - please allow 3-5 business days for this item to ship.


All Calibration Orders Have a 5 to 7 Business Day Lead Time
1 Year Calibration Due Date Unless Otherwise Specified


Onset HOBO Water Level Data Logger Specifications

Data Channels 1 Temperature Channel
1 Pressure/Water Level Channel
Water Level Measurement Range: 0 to 4m (0 to 13ft) - Sea Level; 0 to 7m (0 to 23ft) - 3,000m Altitude
Burst Pressure: 18m (60ft) Depth
Accuracy (Typical): ±0.1% FS, 0.4 cm (0.013 ft) Water
Accuracy (Max): ±0.2% FS, 0.8 cm (0.026 ft) Water
Resolution: 0.14 cm (0.005 ft) Water
Response Time: < 1 second @ stable temperature to 90%
NOTE: Measurement Accuracy Also Depends on Temperature Response Time
Pressure Pressure Range: 0 to 145kPa (0 to 21 psia)
Calibrated Range: 69 to 145 kPA (10 to 21 psia) @ 0°C to 40°C
Burst Pressure: 310 kPa (45 psia)
Raw Pressure Accuracy: ±0.3% FS, 0.43 kPa (0.17 psi) - Max Error
Resolution: <0.014 kPa (0.002 psi)
Temperature Measurement Range: -20°C to 50°C (-4°F to 122°F)
Accuracy: ±0.44°C from 0°C to 50°C (±0.79°F from 32°F to 122°F)
Resolution: 0.10°C at 25°C (0.18°F at 77°F)
Response Time: 10 Minutes in Water to 90% (Typical)
Stability (Drift): 0.1°C (0.18°F) per Year
Data Storage Capacity 21,700 Pressure (Water Level) and Temperature Readings
Sampling Rate 1 Second to 18 Hours (User-Specified)
Logging Modes Fixed Rate or Multiple Logging Intervals ( up to 8)
Power Source 2/3AA, 3.6 Volt Lithium Battery - Factory Replaceable
Battery Life 5 Years @ 1 Minute Sampling Rate
(Dependant Upon Environment and Operating Range)
Time Accuracy ±1 Minute per Month @ 0 to 50°C (32°F to 122°F)
Communications Optical Connection to Setup Data Logger and Download Data
Data Storage Modes Stop When Full or Wrap/Overwrite When Full (FIFO)
Start Modes Immediate Start or Delayed
Offload Modes Offload While Logging; Stop and Offload
Materials Polypropylene Housing and Lanyard; Vitron and Buna-N O-Rings; Ceramic Sensor in Acetyl End Cap; Stainless Steel Screws Suitable for Saltwater
Software Compatibility HOBOware PRO Version 3.5+
OS Compatibility Windows: Windows 10, 8.1, 8 and 7
Mac: OS X 10.9.x, 10.10.x and 10.11.x
Weight Air: 154 grams (5.43 oz)
Fresh Water: 53.9 grams (1.9 oz)
Dimensions 3.18 cm x 15.24 cm (1.25" x 6.0")
Mounting Hole: 6.3mm (0.25")

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