Abstract: A unitary element for use in measuring the total and static pressure of a gas flowing through a duct is disclosed in a preferred embodiment. The element is elongated and hollow, having a continuous, impermeable wall dividing the interior into total and static pressure chambers. In cross section, the element is of aerodynamic or airfoil shape, having a curved forward edge and converging toward the trailing edge adjacent which the outer surfaces are parallel for a short distance. Spaced openings along the forward edge and the upper and lower portions of the rearwardly converging wall portions communicate with the total and static pressure chambers, respectively. Separate manifolds communicate with the total and static pressure chambers of a plurality of such members arranged across an air flow duct to obtain average pressure readings across the cross section of the duct.

Abstract: A HEPA-type, downflow air filter module is disclosed, having a damper supported upon a hollow tube for adjustable movement relative to an opening through which air enters the enclosed chamber or plenum above the filter media. The hollow damper support tube is axially aligned with a passageway between upstream and downstream sides of the center board which conventionally separates the media core into two halves in such filter modules. The passageway is normally sealed by a plug which may be removed from the downstream side of the module for measuring and adjusting air flow into the module, as controlled by the position of the damper which may be adjusted while air flow is being measured.

Abstract: A HEPA-type, downflow air filter module is disclosed, having a damper supported upon a hollow tube for adjustable movement relative to an opening through which air enters the enclosed chamber or plenum above the filter media. The hollow damper support tube is axially aligned with a passageway between upstream and downstream sides of the center board which conventionally separates the media core into two halves in such filter modules. The passageway is normally sealed by a plug which may be removed from the downstream side of the module for measuring and adjusting air flow into the module, as controlled by the position of the damper which may be adjusted while air flow is being measured.

Abstract: A cartridge including a sheet of filtering media in annular form through which air is passed as it moves in a generally toroidal path within an enclosed housing due to rotation of a computer tape disc, or the like, mounted adjacent the cartridge within the housing. The cartridge includes a rigid body portion supporting the filter media in a generally conical plane within the annular body. The body portion is initially formed as two separate, mating halves which engage the media about its inner and outer peripheries when joined.

Abstract: High efficiency air filters are fabricated by forming two end assemblies from rectangular wall members with side plates attached to extend upwardly from opposite sides thereof. A removable wall of expendable material such as ordinary masking tape is applied to the other two sides, extending between the ends of the side plates to form a shallow pan which is filled with a liquid adhesive. The pleated filter media is attached along its two side edges to side wall members having notched ends for mating with the side plates of the end assemblies. One edge of the filter media between the two side walls is immersed in the pool of adhesive and the side walls are attached to the side plates. After the adhesive hardens, the masking tape is removed and the other end assembly is attached in the same manner.