A roller mill module with a fixed grinding roller with a first grind surface rotatably supported within a grind area between a first drive end and a second drive end of a support structure; an adjustable grinding roller with a second grind surface rotatably supported within the grind area; the adjustable grinding roller movable with respect to the fixed grinding roller to adjust a grind gap between the first grind surface and the second grind surface; a drive shaft of the fixed grinding roller and a drive shaft of the adjustable grinding roller extending from the first and the second drive ends of the support structure; and a sample port provided in a front side of the support structure; a sample passage coupled to the sample port extending to a position below the grind area and opposite a sampler stop surface.