Oxygen level displayed as % saturation from 0 - 200% or concentration from 0 - 20 ppm (mg/L). The Tracer has an adjustable altitude compensation ( 0 - 20,000 feet in 1,000 ft increments) and an adjustable salinity compensation (0 - 50 ppt). The memory stores up to 25 data sets with DO and temperature reading and features self-calibration on power up.