Hanna® Waterproof Dissolved Oxygen Meter
This rugged, water-resistant dissolved oxygen meter solves the most common problems associated with field use. Calibration performed with Zero Oxygen Solution (item #652349A, not included), and 100% calibration done in air; automatic temperature compensation assures maximum accuracy under all conditions. Polargraphic probe measures accurately to 0.2 ppm oxygen in seconds; equipped with a 4-m cable for immersion at various depths. Powered by 4 AAA batteries (included) for 100 hr of continuous use.