Patent ID: 7051765

Claim:
An orifice plate comprising: a plate adapted to be positioned in a conduit and extend across a transverse cross-section thereof, said plate defined by a central circular region having a radius R c and a ring-shaped region surrounding said central circular region, said ring-shaped region having a plurality of holes formed therethrough with ones of said plurality of holes centered at each radius R of said ring-shaped region satisfying a radius-independent, flow-based relationship A R =a /( X R V R b ) where A R is a sum of areas of said ones of said plurality of holes having centers at said radius R, X R is a flow coefficient at said radius R that is equal to (ρK) R where ρ R is a density of a fluid that is to flow through the conduit at said radius R and K R is a flow correction factor associated with the fluid that is to flow through the conduit at said radius R, V R is a velocity of the fluid that is to flow through the conduit at said radius R, b is a constant selected to make at least one process variable, associated with the fluid that is to flow through the conduit, approximately equal at each said radius R, and a is a constant that is equal to (X R A R V R b ) at each said radius R.