YSI 55 Dissolved Oxygen & Temperature Meter

Field-proven and easy to use, the YSI 55 D/O Instrument measures dissolved oxygen in mg/L or percent saturation as well as temperature. The YSI 55 has a bright backlit display, automatic push-button calibration, weighted-quick-sinking probe, built-in calibration chamber, low-battery indicator, IP-65 watertight case as well as automatic temperature, salinity, and manual altitude compensation. More details at YSI 55

YSI 550A Waterproof Dissolved Oxygen & Temperature Meter

The new YSI 550A DO features a waterproof, IP-67 rated, impact-resistant case and innovative field-replaceable D/O electrode modules. Measure dissolved oxygen and temperature simultaneously using YSI's proven polarographic technology for oxygen and YSI precision TM thermistors. More details at YSI 550A