Highlighted Features
• 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 (see demo), temperature, and water density.
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 |
Temperature Measurements
|
| 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 |
Logger
|
| 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. |
| Environmental Rating: |
IP68 |
| CE Compliant |
The CE Marking identifies this product as complying with all relevant directives in the European Union (EU).
|
* 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%
