Ultrasonic Flowmeters That Are Insensitive to Suspended Solids

摘要

The report describes the results of an investigation of the performance of state-of-the-art and standard porable ultrasonic Doppler flowmeters that do not require particles or bubbles in the fluid to make an accurate measurement. Both the standard and new state-of-the-art flowmeters measured flow within their claimed accuracy in tap water without any particles or bubbles added. All testing was performed at the U.S. Environmental Protection Agency (USEPA) Test and Evaluation Facility in Cincinnati, Ohio. All testing conformed to Scientific Apparatus Makers Association (SAMA) standards. The test results from both flowmeters are presented so that an easy comparison may be made and that the improvement in performance can be determined. The velocity range of all testing was from 0 - 21.58 ft/sec. The state-of-the-art ultrasonic flowmeter was superior in measuring lower values of flow and performed about the same as the control flowmeter over the upper range of the velocities tested. However, these advancements in ultrasonic technology do not abrogate the normal loss of accuracy above 16.25 ft/sec in tap water. The loss seems to be a function of Reynolds Number.