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HOBO U26-001 Dissolved Oxygen Logger

Brand: Onset HOBO
Product Code: U26-001
HOBO U26-001 Dissolved Oxygen Logger
Ex VAT £1,438.46 Inc VAT £1,726.15

Availability: In stock

SKU: U26-001

Product Description

The HOBO U26 Dissolved Oxygen Logger is a highly precise, low-cost data logger for measuring concentrations of oxygen in lakes, streams, rivers, estuaries, and coastal waters. Used by aquatic biologists, hydrologists, and other research professionals, the HOBO U26 combines the high accuracy, robust performance of industry-leading RDO® Basic (Rugged Dissolved Oxygen) sensor technology with an easy-to-maintain design.

NOTE: If you need to measure DO in saltwater environments, salinity or conductivity measurements are required, which can be conveniently obtained with Onset’s HOBO Conductivity/Salinity Logger (U24-002). If you need DO in Percent Saturation, barometric pressure data is required, which can be logged with a HOBO Water Level Logger (U20-001-04).




  • U26-001 data logger

  • DO sensor cap

  • Protective Guard

  • Calibration Boot with sponge


  • Affordable, high performance dissolved oxygen (DO) monitoring with 0.2 mg/L accuracy

  • Optical DO sensor technology for long-lasting calibration with less maintenance

  • Software corrects for measurement drift from fouling; provides salinity-adjusted DO concentrations and percent saturation

  • Optical USB interface for high-speed, reliable data offload

  • Easy-to-replace DO sensor cap lasts six months


Call +44 (0)1243 558270, click on the webchat box below, or fill out our contact form.

Ex VAT £1,438.46 Inc VAT £1,726.15
Additional Information

Additional Information


Detailed Specifications: 

Dissolved Oxygen  
  Sensor Type Optical
  Measurement Range 0 to 30 mg/L
  Calibrated 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 To 90% in less than 2 minutes
  DO Sensor Cap Life 6 months, cap expires 7 months after initialization
  Temperature Measurement/Operating Range -5 to 40°C (23 to 104°F); non-Freezing
  Temperature Accuracy 0.2°C (0.36°F)
  Temperature Resolution 0.02°C (0.04°F)
  Response Time To 90% in less than 30 minutes
  Memory 21,700 sets of DO and temperature measurements (64 KB total memory)
  Logging Rate 1 minute to 18 hours
  Time Accuracy ±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 (at 5 minute logging)
  Download Type Optical
  Depth Rating 100 m (328 ft)
  Wetted Materials Black Delrin®, PVC, EPDM o-rings, silicone bronze screws; rated for saltwater use
  Size 39.6 mm diameter x 266.7 mm length (1.56 x 10.5 inches)
  Weight 464 g (14.92 oz)
  Description: ce The CE Marking identifies this product as complying with all relevant directives in the European Union (EU).


IMPORTANT: HOBO data loggers require HOBOware software (USB interface cable included w/CD purchase).

Country of Manufacture United States
Onset Product Series U26
Typical Applications Environmental (Outdoor), Field Research, Temperature, Water Quality
Data Available By USB
Measurements Dissolved Oxygen, Temperature
Data sheets

Data sheets

File NameLink
D267_HOBO Dissolved Oxygen Logger - U26-001.pdfDownload