A flowmeter is a vital piece of diagnostic equipment necessary to maintain the life and functionality of a hydraulic system. Measuring flow in GPM (gallons per minute) or LPM (liters per minute), a flowmeter reads the average flow velocity through a transmission line over a constant area. Being able to conduct accurate flow measurements is important because it is an indication of the status of the hydraulic system being monitored. Knowledge of a variation in flow can greatly decrease the cost of maintenance, as well as prevent serious or even hazardous problems arising.