Our HOBO U26 Dissolved Oxygen logger has been part of a multi-year evaluation of DO loggers and sensors by the Alliance for Coastal Technologies (ACT), and the results have been published online. This provides an un-biased report of how our U26 performs in lab and field conditions. Note that our response letter with our added recommendations is attached at the end of this report on pages 58 and 59.

Click here to read.

Highlighted Features

    Affordable, high performance dissolved oxygen (DO) monitoring with 0.2 mg/L accuracy
    Optical DO sensor technology for long-lasting calibration with less maintenance
    HOBOware Pro's Dissolved Oxygen Assistant 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

NOTE: For DO measurements in saltwater, an adjustment for salinity is required. For waters with small changes in salinity (<2 ppt), a salinity meter reading typically provides enough accuracy. For environments with greater salinity changes, we generally recommend the HOBO U24-002-C conductivity logger . If you need DO in Percent Saturation, barometric pressure data is required, which can be logged with a HOBO Water Level Data Logger (U20-001-04).

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
	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
Logger
	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 (16.37 oz)
	Environmental Rating:	IP68
		The CE Marking identifies this product as complying with all relevant directives in the European Union (EU).