Onset U20-001-04-TI User Manual

HOBO U20 Water Level Logger
®
(Part # U20-001-04-Ti)
Inside this package:
• HOBO U20 Water Level Logger
• Calibration certificate
Doc #11219-A, MAN-U20-001-04-Ti
Onset Computer Corporation
Thank you for purchasing a HOBO data logger. With
proper care, it will give you years of accurate and
reliable measurements.

Specifications

Pressure Sensor
Operation range
Factory calibrated range
Burst pressure
Water level accuracy*
Raw pressure accuracy**
Resolution
Pressure response time 90%
Thermal response time (90%)†
* With accurate reference water level measurement and Barometric Compensation Assistant data
** Absolute pressure sensor accuracy includes all pressure drift, temperature, and hysteresis-induced errors
† Maximum error due to rapid thermal changes is approximately 0.5%
Temperature Sensor
Operation range -20° to 50°C (-4° to 122°F)
Accuracy 0.37°C at 20°C (0.67°F at 68°F), see Plot A
Resolution 0.1°C at 20°C (0.18°F at 68°F) (10-bit), see Plot A
Response time (90%) 3.5 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
64K bytes memory (approx. 21,700 pressure and temperature
Memory (non-volatile)
samples)
2.46 cm (0.97 inches) diameter, 15 cm (5.9 inches) length;
Dimensions
mounting hole 6.3 mm (0.25 inches) diameter
Weight Approximately 140 g (4.8 oz)
Wetted materials Titanium, Viton® o-rings, acetyl cap, ceramic sensor
Shock/drop Logger is sensitive to shocks. Handle with care and avoid any impact. Always use proper packaging when shipping the logger.
Fixed-rate or multiple logging intervals, with up to 8 user-defined logging intervals and durations; logging intervals from 1
Logging interval
second to 18 hours. Refer to 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.
The CE Marking identifies this product as complying with the relevant directives in the European Union (EU).
© 2006 Onset Computer Corporation
Part #: MAN-U20-001-04-Ti, Doc #: 11219-A
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
69 to 145 kPa (10 to 21 psia), 0° to 40°C (32° to 104°F)
310 kPa (45 psia) or 18 m (60 ft) depth
Typical error - 0.075% FS, 0.3 cm (0.01 ft) water
Maximum error - 0.15% FS, 0.6 cm (0.02 ft) water
0.3% FS, 0.43 kPa (0.063 psi) maximum error
< 0.014 kPa (0.002 psi), 0.14 cm (0.005 ft) water
< 1 second
Approximately 10 minutes in water to achieve full temperature compensation of the pressure sensor
The HOBO Water Level Logger is designed to measure water level in wells,
rivers, streams, lakes, estuaries, and tidal areas. The logger uses a
maintenance-free absolute pressure sensor and features a durable titanium
housing and ceramic pressure sensor. The logger uses precision electronics to
measure pressure and temperature. Using a reference water level, the
®
HOBOware software automatically converts the pressure readings into
water level readings. Furthermore, the software supports compensation for
temperature, fluid density, and barometric pressure. The logger has enough
memory to record over 21,700 combined pressure and temperature
measurements.
The logger uses an optical USB communications interface (USB-Optic Base
Station, Part # BASE-U-4, with COUPLER2-B) for launching and reading
out the logger. The optical interface allows the logger to be offloaded without
breaking the integrity of the seals. The USB compatibility allows for easy
setup and fast downloads.
HOBOware software is also required for logger operation. Visit
www.onsetcomp.com for compatible software.
2
Accuracy Resolution
1.5
1
0.5
0
-20 0 20
Temperature (°C)
Plot A
40