What is eccentric orifice plate?

The eccentric orifice plate has a hole eccentric. Use full for measuring containing solids, oil containing water and wet steam. Eccentric plates can be used either flange or vena contracta taps, but the tap must be at 1800 or 900 to the eccentric opening. ‘ Eccentric orifices have the bore offset from center to Minimize problems in services of solids-containing materials.

What is eccentric orifice plate