Dissolved oxygen recorder U26-001

One data recorder affordable and accurate measurement of concentrations of'oxygen in lakes streams rivers estuaries and coastal waters. Recommended for research projects aquatic biology and hydrology, this recorder easy to maintain uses the technology of rDO Basic optical OD sensor (Rugged Dissolved Oxygen).
The recorder'dissolved oxygen HOBO U26 was part of a multi-year evaluation of OD recorders and sensors by the Alliance for Coastal Technologies (ACT), whose results are published ICI.
This impartial report describes the performance of HOBO U26 in the laboratory and field.
Note that our letter of reply, with additional recommendations, is attached at the end of the report (pages 58-59).

Technical specifications:

- Affordable and high performance dissolved oxygen (OD) monitoring with 0.2 mg/L accuracy
- DO optical sensor technology for long-term calibration with less maintenance
- The Dissolved Oxygen Software Assistant of HOBOware Pro corrects the measurement drift due to soiling; provides salinity-adjusted OD concentrations and a percentage saturation
- Optical USB interface for fast and reliable data unloading
- The user-replaceable DO sensor cap eliminates the need to return the recorder to the factory to replace the membrane

Note:
For measurements of OD in salt water, an adjustment for salinity is required.
For water with small changes in salinity (For environments with greater salinity changes, we generally recommend' hOBO conductivity recorder U24-002-C.
If you need OD in percentage saturation, barometric pressure data are required, which can be recorded with a water level recorder HOBO U20-001-04.

Features of the dissolved oxygen sensor:

- Sensor type: optical
- Measuring range: 0 to 30mg/L
- Sizing range: 0 to 20 mg/L; 0 to 35 °C (32 to 95 °F)
- Accuracy: ± 0.2 mg/L up to 8 mg/L; ± 0.5 mg/L from 8 to 20 mg/L
- Resolution: 0.02 mg/L
- Response time: 90% in less than 2 minutes
- Life of DO sensor cap: 6 months, ceiling expires 7 months after initialization

Temperature sensor features:

- Measurement range/temperature operation: -5 at 40°C (23 to 104°F); without freezing
- Temperature accuracy: 0.2 °C (0.36 °F)
- Temperature resolution: 0.02 °C (0.04 °F)
- Response time: 90% in less than 30 minutes

Recorder Features:

- Memory: 21,700 sets of OD and temperature measurements (total memory of 64 Kb)
- Log rate: 1 minute at 6 p.m
- Accuracy of the time: ±1 minute per month at 0 to 50°C (32 to 122°F)
- Battery: 3.6 V lithium battery; factory replaceable
- Battery life: 3 years (5 minutes recording)
- Type of download: Optical
- Depth rating: 100 m (328 feet)
- Flottability:
Salt water: 13 g (0.46 oz) negative
Fresh water: 20 g (0.71 oz) negative
- Wet materials : Black Delrin O-rings, PVC, EPDM, silicone bronze screws, evaluated for use in salt water
- Size: 39.6 mm in diameter x 266,7 mm in length (1,56 x 10,5 inches)
- Weight: 272.4 g (9.61 ounces)
- Environmental assessment: IP68

Contents of the box: 

- Dissolved oxygen data recorder HOBO U26-001
- Cap of dissolved oxygen sensor
- Protection guard
- Sizing and sponge boots