Fluid flow rate transducer - uses obstruction induced vortices to measure frequency representing flow rate

摘要

An accurate industry orientated fluid flow transducer is such that obstruction is placed in the fluid flow path so that eddies or vortices are formed and the frequency of these measured to give a measurement of the fluid flow rate. A rectangular or trapezoidal obstruction (11) is placed in the flow path of the fluid in a pipe section (10), so that vortices are formed in the fluid as it flows over the sides (20, 21) of the obstruction. Liq. filled ducts in the obstruction, transmit alternating pressure signals caused by these vertices via flexible leads (30, 31) to a pressure difference transducer (32) and thence to via a monostable multivibrator (34) to a frequency measurement network (35) and display (36). Membranes isolate the internal obstruction liq. from the fluid under examination.