RMG : Glass Rotameter
Omicron Variable Area Flow Meters (Rota-meters) work on the principle of Variable Area. The float moves freely up and down in the tapered boro silicate glass tube with fluid flow from bottom to top. The float takes up a position where buoyancy forces and the float weight are balanced in proportion to flow rate. The vertical position of the float as indicated by scale is the measure of the instantaneous flow rate.