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)
- Resolution 0.10°C at 25°C (0.18°F at 77°F),
- 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 ong
- 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.
- 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%.