What are the Advantage and disadvantage of orifice meter?

Advantages:

Long history of use in various applications

Availability of equipment and data

Measures a wide range of flow rates

Inexpensive when compared to many other flowmeters

Accurate

Disadvantages:

Requires homogeneous fluid

Requires single phase fluid

Requires turbulent flow profile (Reynolds Number greater than or equal to 4000)

Requires axial velocity vector flow

Causes a pressure drop in fluid

Obstructs solids in fluid