Electromagnetic fluid flow meter - has spaced electrodes in contact with fluid, with adjacent electromagnet to produce electrode voltage according to flow

摘要

A pair of spaced electrodes in contact with the fluid are mounted along a line perpendicular to the fluid flow. An elongated electromagnet provides magnetic lines of force perpendicular to both the fluid flow and the line of the electrodes. This generates an electrical potential between the electrodes proportional to the fluid velocity. The electrode leads are oriented w.r.t. to the electromagnet to minimise the quadrature voltage and the electromagnet is bifilar wound and used in a push-pull alternating current driving circuit. The electrode signals are applied to a synchronous detector to generate a direct current voltage proportional to the fluid velocity.