Low-cost, research grade water level data logger (up to 13 ft)
HOBO U20L-04 Water Level (13 ft) Data Logger
The HOBO U20L-004 is a low-cost, research-grade water level data logger for continuously measuring water level and temperature in a wide range of underwater environments. It features 0.1% measurement accuracy, a polypropylene housing for use in both fresh and salt water, and a non-vented design for convenient and hassle-free deployment.
- Self-contained non-vented design enables easy deployment
- Ideal for use in both fresh and saltwater environments, including wells, streams, lakes, wetlands, and tidal areas
- Depths up to 13 feet
- Durable ceramic pressure sensor withstands freezing
- HOBOware Pro software provides easy conversion to accurate water level reading, fully compensated for barometric pressure, temperature, and water density
Note: A calibration certificate is not offered for this logger. If you require a NIST-traceable calibration certificate, please see the U20-001-04 (freshwater) or U20-001-04-Ti (saltwater).
In what environment does this data logger operate?
This data logger operates in outdoor and underwater environments.
What measurements does this data logger support?
The U20L-04 data logger supports the following measurements: Absolute Pressure, Barometric Pressure, Temperature and Water Level
Pressure (Absolute) and Water Level Measurements U20L-04
Operation Range: 0 to 145 kPa (0 to 21 psia); approximately 0 to 4 m (0 to 13 ft) of water depth at sea level, or 0 to 7 m (0 to 23 ft) of water at 3,000 m (10,000 ft) of altitude
Factory Calibrated Range: 69 to 145 kPa (10 to 21 psia), 0° to 40°C (32° to 104°F)
Burst Pressure: 310 kPa (45 psia) or 18 m (60 ft) depth
Water Level Accuracy*: Typical error: ±0.1% FS, 0.4 cm (0.013 ft) water; Maximum error: ±0.2% FS, 0.8 cm (0.026 ft) water
Raw Pressure Accuracy**: ±0.3% FS, 0.43 kPa (0.063 psi) maximum error
Resolution: <0.014 kPa (0.002 psi), 0.14 cm (0.005 ft) water
Pressure Response Time (90%)***: <1 second at a stable temperature; measurement accuracy also depends on temperature response time
Operation Range: -20° to 50°C (-4° to 122°F)
Accuracy: ±0.44°C from 0° to 50°C (±0.79°F from 32° to 122°F), see Plot A in manual
Resolution: 0.10°C at 25°C (0.18°F at 77°F), see Plot A in manual
Response Time (90%): 10 minutes in water (typical)
Stability (Drift): 0.1°C (0.18°F) per year
Real-time Clock: ±1 minute per month 0° to 50°C (32° to 122°F)
Battery: 2/3 AA, 3.6 Volt lithium, factory-replaceable
Battery Life (Typical Use): 5 years with 1 minute or greater logging interval
Memory (Non-volatile): 64K bytes memory (approx. 21,700 pressure and temperature samples)
Weight: Approximately 154 g (5.43 oz) in air Approximately 53.9 g (1.9 oz) in fresh water
Dimensions: 3.18 cm (1.25 inches) diameter, 15.24 cm (6.0 inches) length; mounting hole 6.3 mm (0.25 inches) diameter
Wetted Materials: Polypropylene housing and lanyard; Viton and Buna-N O-rings; ceramic sensor in acetyl end cap; stainless steel screws suitable for saltwater
Logging Interval: Fixed-rate or multiple logging intervals, with up to 8 user-defined logging intervals and durations; logging intervals from 1 second to 18 hours. Refer to the HOBOware User’s Guide for details.
Launch Modes: Immediate start and delayed start
Offload Modes: Offload while logging; stop and offload
Battery Indication: Battery voltage can be viewed in status screen and optionally logged in datafile. Low battery indication in datafile.
* Water Level Accuracy: With accurate reference water level measurement, known water density, accurate Barometric Compensation Assistant data, and a stable temperature environment.
** Raw Pressure Accuracy: Absolute pressure sensor accuracy includes all sensor drift, temperature, and hysteresis-induced errors.
*** Changes in Temperature: Allow 20 minutes in water to achieve full temperature compensation of the pressure sensor. Maximum error due to rapid thermal changes is approximately 0.5%.