Flow Measurement using Bernoulli Equation

Comparison of Flow Meters

\[v_2 = \frac{1}{\sqrt{1-(D_2/D_1)^4}}\sqrt{\frac{2(P_1-P_2)}{\rho}}\]

\(P_1-P_2\) is variable with orifice and venturi meters; and, \(D_2/D_1=\beta\) is a variable with rotameter.

Orifice and venturimeters are also known as variable head meters (or, constant area meters); and, rotameter is a variable area meter (or, constant head meter).