Glass tube rotameter,“Telelin” make high accuracy fully enclosed online direct reading glass tube rotameters are relatively simple and reliable instruments for continuous flow rate indication. This rotameters consists of a vertical mounted, calibrated tapered tube with float inside and a scale directly calibrated as per flow range taking into account operating Sp. Gr. Density and operating viscosity. Your line fluid raises the float in tapered glass Tube, Area increases as float moves upward thereby showing the exact (Increasing) flow.