HOBO U20L-04 is a research-grade data logger for continuous monitoring of water level and temperature at depths up to 13-ft (4m) in wide range of underwater environments; for use in freshwater or saltware. This logger features 0.1% measurement accuracy, a polypropylene housing for use in both freshwater and saltwater, and a non-vented design for convenient and hassle-free deployment.
IMPORTANT INFORMATION:
Requires HOBOware Pro software and either a U-DTW-1 Waterproof Shuttle or the Base-U-4 Optic USB Base Station for configuration and data offload.
Highlighted Features
• Self-contained, non-vented design enables easy deployment
• Ideal for use in both freshwater and saltwater environments, including wells, streams, lakes, wetlands, and tidal areas
• Depths up to 13, 30, or 100 feet depending on model
• HOBOware Pro software provides easy conversion to accurate water level reading, fully compensated for barometric pressure, temperature, and water density
Specifications
| Pressure 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 |
| 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 stable temperature; measurement accuracy also depends on temperature response time |
| Temperature Measurements (U20L-04) | |
| 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 | 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 |
5 years with 1 minute or greater logging interval |
|
Memory (Non-Volatile) Weight |
64K bytes memory (approx. 21,700 pressure and temperature samples) 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 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 acetal 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 software manual. |
| 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 |