Measures dissolved oxygen to determine water quality in environmental testing, labs, industrial and municipal waste water, aquariums and fish hatcheries. Automatic temperature compensation as well as manual compensation for salinity and altitude (all factors directly effecting DO readings). Simultaneously displays dissolved oxygen (in % or mg/L) and temperature readings (in °C or °F). Review 99 data points readings directly on the large backlit LCD. Features simple one-button calibration to air. The electrolyte level is visible through the transparent galvanic probe with built-in temperature sensor and a 3.5 meter cord. The DO probe heads include built in membranes and screw on and off for easy replacement. Also functions as a pH and conductivity meter when used with the optional probes. Comes in a hard carrying case complete with pB (lead) free Galvanic DO probe with 9’ cable, 2 spare probe heads with membranes installed, electrolyte and 4 AAA batteries. NOTE: Probes for this meter have 1 year warranty only.