Test apparatus employing pneumatic bridge for testing pneumatic flow resistance and related methods

U.S. Patent Number: 5347847

Abstract: In an apparatus for testing pneumatic flow resistance of a test component, such as an air filter useful in a system for admixing parenteral solutions, a pneumatic bridge has two branches connected, via a filter, a flow restrictor, and a flowmeter, to a source of gas under regulated pressure. Each branch comprises two arms with a centerpoint. The bridge has a pressure transducer connected between the centerpoints and arranged to detect pressure imbalances in the bridge. Each arm comprises a flow restrictor, namely a needle valve, which is calibrated via a vernier head. The valves are adjustable to balance the bridge. In one arm, in which the needle valve can be fully opened, the test component is connectible to constitute a flow restrictor. The transducer produces an output displayed via a digital voltmeter, which may be calibrated.

Inventors: Ogden; John E. (Libertyville, IL), Bryant; Peter L. (Libertyville, IL), Caron; Lois L. (McHenry, IL)

Assignee: Abbott Laboratories (Abbott Park, IL)

Application Number: 07/993,199

Issued: 1994-09-20

Expired: 2006-09-20

Classes: 73/37 ; 116/273; 222/71; 73/37.5

Field of search: 116/273 73/861,37,37.5,861.52,196 222/71 261/Dig. 27/

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