FLOWTECHVariable Area Flow Meters TINYROTAMETERS are intended for general in line metering applications (i.e. forGas & Liquid) for low flow measurement and for purging applications. Theseare available in Acrylic Body Tube and Glass Tube design. These are working on theprinciple of Variable Area. The float moves freely up and down tapered Acrylic BodyTube OR Glass Tube with fluid flow from bottom to top. The float takes up aposition where buoyancy forces and the float weight are balanced in proportionto flow rate. The Vertical position of the float as indicated by scale is themeasure of the instantaneous flow rate.