Maintaining a precise flow rate is critical to a flow meter’s accuracy. There are several different methods of ultrasonic meter calibration, with the most effective method typically being determined by the type of system undergoing calibration and its intended purpose. Ultrasonic meter calibration is performed by placing a flow standard in line with the flow meter, precisely measuring the rate of flow in accordance with nationally recognized standards. If the structural integrity of a system is intact and the system is free of any types of flaws between the standard and meter, the two meters should have the same flow rate. The two types of calibration most commonly used are pipeline-based calibration and pressurized loop calibration.