Yokogawa's standard Vortex Flow Meter.
Yokogawa released the world's first vortex flow meter in 1968. Thanks to its long-term stability and high accuracy, our customers have achieved significant improvements in productivity over the past forty years. In response to ever changing market needs, Yokogawa has gone on to release high temperature, cryogenic, dual-sensor, reduced bore, and FOUNDATION Fieldbus communication versions of this product.
Yokogawa's forty+ years of Vortex Flow Meter innovation.
Vortex Flow Meters use the Von Karman Effect to measure the rate of flow of a fluid or gas.
Early in the 20th century, a Hungarian-American mathematician and physicist, Theodore von Karman, discovered that a fluid or gas flowing perpendicularly pass a bluff body would generate alternating vortices on both sides of the body. The path of these vortices is called the Von Karman Street. The easiest way to visual this is to think of a flag on a flag pole. The flag pole is the bluff body and the flag "waves" due to the flag being in the Von Karman Street.
Von Karman found that if the frequency of these vortices was measured, that the frequency is proportional to the flow rate that is generating the vortices. This frequency is called the Karmen Vortex Frequency. The relationship of the fequency and the flow velocity can be mathematically expressed with the following formula: