Importance

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Abstract

Method and apparatus for determining a face respirator fit for a particular respirator on a particular person wherein after first placing the respirator on the person's face, the air interiorly to the facepiece is partially evacuated while the subject holds his breath and clamps off his nostrils, the air which then leaks into the facepiece through leakage paths between the facepiece and the wearer's face is measured by a mass flow meter in line with a vacuum source which maintains a constant negative pressure interiorly to the facepiece, the test being accomplished over a relatively short period of time. The apparatus of the invention includes modifying the respirator by sealing off the normal inspiratory openings, i.e., the inhalation filters, and in their places having ports which connect to the mass flow meter and a pressure monitoring transducer. The mass flow meter is then connected with the source of vacuum wherein the pressure transducer, after an initial negative pressure is introduced interiorly to the facepiece, maintains that negative pressure by opening and closing a valve connected with the vacuum source. Leakage air into the facepiece is constantly withdrawn through the mass flow meter and thus the measurement of the leaking air is indicative of the quality of air tightness sealing of the respirator to the face of the wearer.

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First Claim