Patents by Inventor Francis P. Liu

Francis P. Liu has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Method and apparatus for determining the concentration of readily oxidizable organic vapors in gas samples
    Patent number: 5552324
    Abstract: A reagent, an apparatus and a method for semi-quantitatively estimating the concentration of readily oxidizable organic vapors in a gas sample, as for example ethanol in a human breath sample, is disclosed. The ethanol-sensitive solid indicator is a solid support which contains a permanganate salt and is wetted by a strongly acidic or alkaline solution. In the presence of ethanol the indicator produces a clearly visible color change. The apparatus contains the indicator and provides a pathway for a gas sample through the indicator. The method allows estimation of the organic-vapor content of a gas sample by comparing the volume of indicator which changes color in response to the gas sample with the volume which changes color in response to a known-concentration standard.
    Type: Grant
    Filed: May 23, 1994
    Date of Patent: September 3, 1996
    Assignee: Supelco, Inc.
    Inventor: Francis P. Liu