Unlike many Vernier sensors that have collection units changed by selecting the desired unit from the Experiment menu in Logger Pro or by tapping on the live reading of the meter screen when using LabQuest, the Optical DO Probe has a switch on the cable box near the white connector. The switch allows the user to select between units of mg/L or % saturation.

See Choosing Units section in the Optical DO Probe Specifications and User Guide for more information about these units of measurement.