伝播時間差式超音波流量計の精度に及ぼす速度分布の影響

抄録

The transit time ultrasonic flow meter (TOF) has been widely applied in industry due to its advantages, such as applicability to larger diameter pipe, small pressure loss, etc. Since the TOF derives flow rate from the change of the trantis time between two sensors, the accuracy of TOF is strongly influenced by velocity profile in the pipe. Velocity profile is influenced by not only the upstream condition but also the shape of tranducer pocket on the pipe wall. In this paper, in order to evaluate influence of velocity distribution on the accuracy of TOF, a system to measure the tiransit time and the velocity profile simulataneouly was developed. In experiments, an obstacle plate was installed to distort velocity profiles. The velocity profiles and their transit times of ultrasonic pulses were compared. As a result, line-averaged velocities calculated from the transit time were good agreement with the line-averaged velocities obtained by using UDM.