US Patent 7281436 Wedge flow meter with conditioner

A primary flow measuring element comprising a cylindrical body having an axis and an interior surface defining a fluid flow path and having at least one differential pressure producing segmental wedge attached to the interior surface of the cylindrical body with high and low pressure sensing ports disposed in said cylindrical body on the upstream and downstream sides of the at least one segmental wedge respectively and having at least one conditioning segmental wedge attached to the interior surface of the cylindrical body at a position upstream from the at least one differential pressure producing segmental wedge.