Rotameters

Operating Principle : Glass Tube Rotameter is basically a Variable Area Flow Meter. The differential pressure across the annulus area is constant and the flow rate is measured as a function of the annulus area. Glass Tube Rotameters consist of a tapered glass tube mounted vertically in a frame with the small diameter at the bottom and large end up. The tube contains a free moving float that rests on the stopper at the base of the tube. When the liquid flows, the float rises until its weight is balanced by the up thrust of the fluid and the float reaches a position of equilibrium. At this position it indicates the instantaneous rate of flow. The flow rate can be read from the adjacent scale..