High frequency valve noise as a cause of errors in ultrasonic flowmeters

High frequency noise from control valves and pressure regulators for gas service is a potential source of errors in ultrasonic flowmeters. A method is proposed to measure high frequency valve noise in a reproducible way. Results are presented of in-duct high frequency noise measurements for control valves and for pressure regulators. High frequency noise levels of valves are compared to signal levels of ultrasonic flowmeters