A conduit having an inside diameter Dp and an orifice plate configured to be positioned in the conduit, wherein the conduit and the orifice plate are configured so that a fluid having a given density and viscosity can flow through the conduit and the orifice plate , said orifice plate comprising: a central opening and a ring-shaped region , wherein the central opening has a diameter D 1 and the ring-shaped region is located at a radius R 2 from the center of the orifice plate and surrounds the central opening; wherein the inlet of the central opening has a contoured edge; wherein the ring-shaped region includes two or more openings formed through the orifice plate with a center of each opening centered on the radius R 2 , wherein the radius R 2 satisfies a relationship, R 2 = (D p + (D 1 + 2(RCo)))/4, where RCo is a radius of the contoured edge of the central opening ; wherein the two or more openings each have a diameter D 2 , each of the two or more openings can be configured to equally satisfy a velocity distribution relationship V 2 V 1 = 1 − R 2 R p b ; and wherein the diameter D 2 of each of the two or more openings and the diameter D 1 of the central opening can be configured to equally satisfy a Reynolds matching relationship N RE , 1 = N RE , 2 wherein: N RE , 1 = D 1 ρV 1 μ ; N RE , 2 = D 2 ρV 2 μ ; N RE, 1 is a Reynolds number for the diameter D 1 of the central opening; N RE, 2 is a Reynolds number for the diameter D 2 of each of the two or more openings; V 1 = velocity of a flow through the central opening; V 2 = velocity of a flow through the center of each of the two or more openings; ρ = density of the fluid; μ = viscosity of the fluid; and R p = radius of the conduit. a central opening and a ring-shaped region , wherein the central opening has a diameter D 1 and the ring-shaped region is located at a radius R 2 from the center of the orifice plate and surrounds the central opening; wherein the inlet of the central opening has a contoured edge; wherein the ring-shaped region includes two or more openings formed through the orifice plate with a center of each opening centered on the radius R 2 , wherein the radius R 2 satisfies a relationship, R 2 = (D p + (D 1 + 2(RCo)))/4, where RCo is a radius of the contoured edge of the central opening ; wherein the two or more openings each have a diameter D 2 , each of the two or more openings can be configured to equally satisfy a velocity distribution relationship V 2 V 1 = 1 − R 2 R p b ; and wherein the diameter D 2 of each of the two or more openings and the diameter D 1 of the central opening can be configured to equally satisfy a Reynolds matching relationship N RE , 1 = N RE , 2 wherein: N RE , 1 = D 1 ρV 1 μ ; N RE , 2 = D 2 ρV 2 μ ; N RE, 1 is a Reynolds number for the diameter D 1 of the central opening; N RE, 2 is a Reynolds number for the diameter D 2 of each of the two or more openings; V 1 = velocity of a flow through the central opening; V 2 = velocity of a flow through the center of each of the two or more openings; ρ = density of the fluid; μ = viscosity of the fluid; and R p = radius of the conduit. N RE, 1 is a Reynolds number for the diameter D 1 of the central opening; N RE, 2 is a Reynolds number for the diameter D 2 of each of the two or more openings; V 1 = velocity of a flow through the central opening; V 2 = velocity of a flow through the center of each of the two or more openings; ρ = density of the fluid; μ = viscosity of the fluid; and R p = radius of the conduit. <EOS>