| Pressure and Water Level Measurements U20-001-01 and U20-001-01-Ti | |
| Operation Range | 0 to 207 kPa (0 to 30 psia); approximately 0 to 9 m (0 to 30 ft) of water depth at sea level, or 0 to 12 m (0 to 40 ft) of water at 3,000 m (10,000 ft) of altitude |
| Factory Calibrated Range | 69 to 207 kPa (10 to 30 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: ±0.05% FS, 0.5 cm (0.015 ft) water Maximum error: ±0.1% FS, 1.0 cm (0.03 ft) water |
| Raw Pressure Accuracy** | ±0.3% FS, 0.62 kPa (0.09 psi) maximum error |
| Resolution | <0.02 kPa (0.003 psi), 0.21 cm (0.007 ft) water |
| Pressure Response Time (90%)*** | <1 second; measurement accuracy also depends on temperature response time |
| Temperature Measurements (All Models) | |
| 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 |
| Resolution | 0.10°C at 25°C (0.18°F at 77°F), see Plot A |
| Response Time (90%) | 5 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 | Stainless steel models: approximately 210 g (7.4 oz) Titanium models: approximately 140 g (4.8 oz) |
| Dimensions | 2.46 cm (0.97 inches) diameter, 15 cm (5.9 inches) length; mounting hole 6.3 mm (0.25 inches) diameter |
| Wetted Materials | Titanium, Viton® o-rings, acetyl cap, ceramic sensor |
| 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. |
* 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 10 minutes in water to achieve full temperature compensation of the pressure sensor. Maximum error due to rapid thermal changes is approximately 0.5%.
