Rotameter

h (Rotameter rise, in)
rho (Density, lb per ft3)
V_F (Float volume, in3)
D_F (Float diameter, in)
rho_F (Float Density, lb per ft3)
D_b (Tube diameter at the bottm, in)
D_t (Tube diameter at the top, in)
L_t (Tube length, in)
C_R (Rotameter coefficient)