Common choices include electromagnetic flow meters for conductive aqueous emulsions, Coriolis meters where mass flow accuracy is needed, and positive displacement meters in smaller systems if viscosity range is controlled. Mag meters are popular because they have no moving parts and handle emulsions well, but installation needs good straight runs and proper grounding. Coriolis meters provide density and mass flow but cost more and require stable mounting. Any meter needs calibration against a known volume or weigh bridge, and the control system must compensate for temperature driven viscosity changes that affect pump slip.