Measurement and control of fluid flow

Apparatus for measuring flow rates of fluids comprising a vertical conduit, a float element having a magnetic responsive material associated therewith positioned in said conduit, a stop element positioned in said conduit which limits the motion of said float element, electromagnetic means positioned above said stop element, means for gradually increasing the current to said electromagnetic means to thus increase the magnetic force of said electromagnetic means so as to move said float element away from said stop element, said means for gradually increasing current to said electromagnetic means increasing current in a gradual stepwise manner to accurately measure the magnetic force required for the float to leave the stop element, means for detecting the initial departure of the float from the stop element, and means for relating fluid flow to the degree of current required to move said float element away from said stop element.

Apparatus for measuring flow rates of fluids comprising a conduit, a float element having a magnetic responsive material associated therewith positioned in said conduit, a stop element positioned in said conduit which limits the motion of said float element in the downstream direction, electromagnetic means positioned in an upstream portion about said conduit before said stop element, means for gradually increasing the current to said electromagnetic means to thus increase the magnetic force of said electromagnetic means so as to move said float element away from said stop element and against the direction of fluid flow, means for detecting the initial departure of the float element away from the stop, and means for relating fluid flow to the degree of requisite increase of current to cause movement of said float element away from said stop element, said means for gradually increasing current comprising an oscillator, and an integrator, and which apparatus further contains a digital counter, said oscillator producing a wave train sent to the digital counter and integrator, said integrator controlling the current to the electromagnetic means proportional to the output of the integrator, said oscillator being turned off when said float element departs from said stop element, the accumulated counts in the digital counter being directly related to fluid flow rate.