Metal Tube Rotameter is basically o variable area flowmeter. The differential, pressure across the annulus area is constant and the Flowrate is measured as a function of the position of annulus area created by float position. The position of the float is sensed by a magnet and indicated on the dial in terms of flow rate. • Line Size From 15 NB To 100 NB • Flow Range Between 25 LPH to 63000 LPH • Accuracv +/- 2% Of Full Scale