SPECIFICATIONSDisplay13 mm ( 0.5" ) LCD, 3 1/2 digits.Measurement RangeDissolved Oxygen - 0 to 20.0 mg/L.Resolution0.1 mg/L..Accuracy± 0.4 mg/L. (after calibration within 23± 5 ℃)Sensor Temp.CompensationAutomatic from 0 to 40℃.Panel adj. knobZERO ...