YSI Model 55 Handheld Dissolved Oxygen Meter; with 12 ft. (3.7m) cable

The YSI® Model 55 simultaneously displays temperature in degrees Celsius and dissolved oxygen in either mg/L or % air saturation with all readings being temperature compensated. Compensation for barometric pressure is automatically calculated by entering in your local altitude, and salinity compensation is automatic once you enter the approximate salinity of your sample in parts per thousand. Even field calibration can be easy due to a built in calibration chamber with a small sponge. The YSI 55 features a large, easy-to-read, back-lit LCD, a strain relief where the probe connects to the cable, and error messages on the LCD that help pinpoint problems and possible causes. Includes six AA size batteries.