An aftertreatment system includes an introduction conduit and a mixer disposed within the introduction conduit. The introduction conduit is centered on a mixer body center axis. The mixer includes a mixer body, an exhaust sampling flange, an outlet flange, and an outlet tube. The exhaust sampling flange is coupled to the mixer body at a location adjacent to a second end of the mixer body. The exhaust sampling flange includes exhaust sampling flange apertures arranged in an array that extends circumferentially around the mixer body center axis. The outlet flange is coupled to the second end downstream of the exhaust sampling flange. The outlet flange includes an outlet flange aperture. The outlet tube is coupled to the outlet flange. The outlet tube is in fluid communication with at least one of the exhaust sampling flange apertures. The outlet tube extends over a portion of the outlet flange aperture.