The rotameter is an analog device that measures the flow rate of a fluid as the material pushes on a floating indicator. Rotameters help to ensure that system fluid flow rates are normal and passageways are not excessively restricted or blocked, which could dramatically raise fluid pressure. The rotameter is calibrated in both liters per minute (L/min) and gallons per minute (gal/min), and the clear-tapered tube permits visual inspection of the internal fluid and observation of trapped air bubbles, dirt, and debris within a system loop.