Onset HOBO U26 Dissolved Oxygen Logger Demonstrates Accuracy and Reliability in Third-Party Study

BOURNE, MA, February 27, 2017 – Onset, a world leader in data loggers for water quality monitoring, today announced that The Alliance for Coastal Technologies (ACT) has released an independent verification study of Onset’s HOBO® U26 Dissolved Oxygen Logger as part of a multi-year evaluation of in situ dissolved oxygen (DO) sensors. Conducted during 2015-2016, the unbiased verification characterized performance measures of accuracy and reliability in a series of controlled laboratory studies and field mooring tests in diverse coastal environments.

The HOBO U26—one of two stand-alone DO loggers in the study —performed well in these tests, demonstrating high accuracy over a wide range of DO, temperature, and salinity conditions. The HOBO U26 also successfully maintained its accuracy over a long-term (56 days) lab testing period.

The verification included several months of laboratory testing and three field deployments in freshwater, estuarine, and oceanic environments. Instrument accuracy and precision for the HOBO U26 was tested under nine combinations of temperature and salinity over a range of DO concentrations from 10% to 120% of saturation.

Results indicated that the HOBO U26 operated reliably throughout these challenging tests. The ACT study also found that the response of the HOBO U26 RDO sensor showed good linearity during field testing across freshwater, brackish water, and oceanic water salinity ranges. 

“We are very pleased to see the HOBO Dissolved Oxygen Logger perform so well in this independent study, especially considering the HOBO is a fraction of the cost of most of the other DO logging systems,” said Paul Gannett, Onset product marketing manager.  

The field tests confirmed the importance of keeping the sensor clean in high-fouling environments. Onset recommends regular cleaning to remove fouling to maintain the performance of the HOBO U26, as well as using field calibration to achieve the best accuracy and compensate for measurement drift from fouling. 

Overall, the ACT results confirm the high performance and reliability of the HOBO U26, available at a lower cost than other high-end oceanographic systems. 


Onset Computer Corporation
1-800-564-4377 / 508-759-9500

About Onset 

Onset is a leading supplier and trusted manufacturer of data loggers and monitoring solutions used to measure, record, and manage data for improving the environment and preserving the quality of temperature-sensitive products. Based on Cape Cod, Massachusetts, Onset has been designing and manufacturing its products on site since the company's founding in 1981.