Flow resistor with laminar flow for a flow meter

摘要

A flow resistor with laminar flow for a flow meter, for example for determining the air permeability of a specimen, has a plurality of separate flow ducts arranged parallel to one another, junctions for the flow to be measured at the front faces of the ends of the flow ducts, as well as taps extending at right angles to the flow direction for measuring the pressure drop at a central flow duct. Arranged between at least one junction and the associated front face of the end of the flow ducts is a movable perforated plate, in particular a rotatable perforated disc, having a plurality of passage openings which are connected on one side to the associated junction and on the other side can be aligned in respectively assigned positions of the perforated disc with a different number of flow ducts. As a result, the entire available flow volume can be split into a plurality of flow ducts, resulting in coverage of various measurement ranges.