Hobo Conductivity Data Logger for Saltwater, U24-002
Product Code: U24-002
The HOBO U24-002 Saltwater Conductivity/Salinity Data Logger is a rugged, compact data logger designed for monitoring conductivity, salinity and temperature in saltwater environments. It is particularly suited to coastal waters and saltwater bays where relatively small changes in salinity need to be detected, including changes associated with rainfall, upwelling and freshwater discharge events.
The U24-002 uses a non-contact capacitive conductivity sensor with an inert titanium pentoxide coating. Because the sensor does not use traditional electrodes that contact the water, it avoids many of the corrosion and tarnishing problems associated with conventional conductivity sensors. The sensor is also readily accessible for cleaning and removal of fouling and trapped air bubbles.
The logger provides two selectable conductivity ranges: 100–10,000 µS/cm and 5,000–55,000 µS/cm. It measures actual conductivity and temperature, while specific conductance at 25°C and salinity can be calculated using the HOBOware Conductivity Assistant. Salinity calculations use the Practical Salinity Scale 1978 (PSS-78).
With 64 KB of memory, the U24-002 can record up to 18,500 temperature and conductivity measurements when using one conductivity range, or approximately 11,500 sets when both ranges are used. Sampling intervals can be programmed from 1 second to 18 hours, including multiple-rate logging with up to eight user-defined intervals. The logger has a typical battery life of approximately three years when logging at one-minute intervals and can be deployed to depths of up to 70 m (225 ft).
• Memory: 18,500 temperature and conductivity measurements when using one conductivity range; 14,400 sets of measurements when using both conductivity ranges (64kbytes).
• Sample rate: 1 second to 18 hrs, fixed or multiple-rate sampling with up to 8 user-defined sampling intervals.
• Battery life: 3 years (@ 1 min logging).
• Maximum Depth: 70 m (225').
• Operating Range: -2 to 36°C (28° to 97°F) - non freezing.
• Weight: 6.82 oz.; buoyancy in freshwater: -2.11 oz.
• Size: 1.25" diameter x 6.5", 1/4" hole.
• Conductivity Range (Calibrated Range): High Range, 5,000 to 55,000 uS/cm; Low Range, 100 to 10,000 uS/cm
• Temperature Range: 28°F to 97°F (-2°C to 36°C).
• Conductance Accuracy (Calibrated Range): 3 Low Range, 3% of reading or 50 uS/cm, whichever is greater. High Range, up to 5% of reading, in waters within a range of ±3,000 uS/cm of the calibration point (waters with greater variation can have substantially greater error).
• Temperature Accuracy: 0.2°F (0.1°C).
• Conductivity Resolution: 2 uS/cm.
• Temperature Resolution: 0.02°F (0.01°C).
• Drift: Conductivity, up to 12% sensor drift per month, exclusive of drift from fouling.
• Response time: 1 second to 90% of change.
Note: HOBO data loggers require either the HOBO Waterproof Shuttle or Universal Optic USB Base Station and a USB Cable. (Note: A USB cable is included w/ HOBOware Pro CD or USB software purchase). HOBOware Pro is required when using the U-DTW-1 HOBO Waterproof shuttle.
