HOBO® U24 Conductivity Logger (U24-00x) Manual
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Corporation. Delrin is a registered trademark of DuPont. All other trademarks are the property of their respective companies.
14787-A MAN-U24-x
The HOBO U24 data logger family measures actual conductivity and
temperature, and can provide specific conductance at 25°C and salinity
with the HOBOware® Conductivity Assistant. These easily deployable,
rugged loggers provide the data you need for monitoring water purity,
the impact of pollutants, salt water intrusion, and coastal ecosystems.
The U24-001 model is ideal for deployment in fresh water, while the
U24-002 model is designed for saltwater bays and estuaries. There is
also an optional U2X Protective Housing accessory (HOUSING-U2X)
available for both HOBO U24 models to further protect the logger and
simplify mounting in harsh environments.
Specifications
U24-001
U24-002
Measurements
Actual Conductivity, Temperature, Specific
Conductance at 25°C (calculated)
Actual Conductivity, Temperature, Specific
Conductance at 25°C (calculated), Salinity
(calculated using PSS-78, the Practical Salinity
Scale 1978)
Conductivity Calibrated
Measurement Ranges
Low Range: 0 to 1,000 µS/cm
Full Range: 0 to 10,000 µS/cm (see Plot B on
next page for specific conductance; see Plot C
on next page for a comparison of ranges)
Low Range: 100 to 10,000 µS/cm
High Range: 5,000 to 65,000 µS/cm (see Plots
A and B on next page for salinity and specific
conductance; see Plot C for a comparison of
ranges)
Conductivity Calibrated Range –
Temperature Range
5° to 35°C (41° to 95°F)
5° to 35°C (41° to 95°F)
Conductivity Extended Ranges
Low Range: 0 to 2,500 µS/cm
Full Range: 0 to 15,000 µS/cm
Low Range: 50 to 30,000 µS/cm
High Range: 1,000 to 65,000 µS/cm
(readings below these ranges reported as 0)
Temperature Measurement Range
0° to 50°C (32° to 118°F)
0° to 50°C (32° to 118°F)
Specific Conductance Accuracy
(in Calibrated Range)
Low Range: 3% of reading, or 5 µS/cm, and
Full Range: 3% of reading, or 20 µS/cm,
whichever is greater, after correction with
Conductivity Data Assistant
3% of reading, or 50 µS/cm, whichever is
greater, after correction with Conductivity
Data Assistant
Conductivity Resolution
1 µS/cm
2 µS/cm
Temperature Accuracy (in
Calibrated Range)
0.1°C (0.2°F)
Temperature Resolution
0.01°C (0.02°F)
Conductivity Drift
Less than 3% sensor drift per year in saltwater, exclusive of drift from fouling
Response Time
1 second to 90% of change (in water)
Operating Range
0° to 50°C (32° to 122°F) - non-freezing
Memory
18,500 temperature and conductivity measurements when using one conductivity range; 14,400
sets of measurements when using both conductivity ranges (64 KB total memory)
Sample Rate
1 second to 18 hrs, fixed or multiple-rate sampling with up to 8 user-defined sampling intervals
Clock Accuracy
± 1 minute per month
Battery
3.6 Volt lithium battery
Battery Life
3 years (at 1 minute logging)
Maximum Depth
70 m (225 ft)
Weight
193 gm (6.82 oz), buoyancy in freshwater: -59.8 gm (-2.11 oz)
Size
3.18 cm diameter x 16.5 cm, with 6.3 mm mounting hole (1.25 in. diameter x 6.5 in., 0.25 in.
hole)
Wetted Housing Materials
Delrin®, epoxy, stainless steel retaining ring, polypropylene, Buna rubber O-ring, titanium
pentoxide (inert coating over sensor); all materials are suitable for long-term use in saltwater
The CE Marking identifies this product as complying with all relevant directives in the European
Union (EU).
