GEAR MEASURING AIR PERMEABILITY Russian patent published in 1999 - IPC

FIELD: study of properties of concrete and other porous materials for air permeability. SUBSTANCE: gear measuring air permeability of material has working chamber with hole for air release, vacuum gauge, device creating vacuum, indication unit, rarefaction release valve, chamber-receiver. Indication unit includes air distributor, U-shaped branch pipe with scale of liquid level partially filled with liquid. Air distributor is also made in the form of branch pipe divided in middle by narrowing hole. First and second holes joined leak-tight to proper ends of U-shaped branch pipe are made in walls of branch pipe on both sides of narrowing hole. Outlet hole of working chamber is connected to first end of branch pipe of air distributor and second end of this branch pipe is joined to chamber-receiver on which vacuum gauge and rarefaction release valve are located. Part of U-shaped branch pipe connected to first hole of branch pipe of air distributor has larger section than other part made from transparent material and joined to second hole of branch pipe of air distributor. Device creating vacuum has T-shaped branch pipe and hollow chamber manufactured from elastic material, for instance rubber bulb, connected to middle part of T-shaped branch pipe. Two other ends of it are fitted with valves. One end of T-shaped branch pipe is linked to receiver. Surface of fitting of working chamber to tested object is divided into external and internal parts with the use of annular groove communicating with hole for air release. EFFECT: simplified design, decreased mass and size indices, exclusion of need in electric energy source and expanded technical capabilities while measuring air permeability of wide range of objects under real conditions. 1 dwg