This module consists of a duct in which there is situated a flat plate. The flat plate is rough on one side and smooth on the other, providing different surface conditions for the formation of a boundary layer. To extend the experiments, removable duct liners can be added or removed to change the pressure gradient in the direction of flow.
The total pressure (and thus velocity) at various distances from the plate surface is measured by a flattened Pitot tube which is positioned by a micrometer. The pitot tube connects to the AF10a manometer (ancillary) via a flexible tube fitted with a quick-release coupling.