Patents by Inventor Helmut Apfel

Helmut Apfel 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).

  • Control arrangement for the chromatography of liquid
    Patent number: 5004538
    Abstract: A control arrangement for a liquid chromatograph is disclosed which generates a correction factor to compensate for non-uniform passage of eluate past the detector of the chromatograph. A flow meter measures the actual flow of eluate from the detector and generates a representative signal which is compared with a standard signal representative of the desired flow rate to generate the correction signal.
    Type: Grant
    Filed: March 2, 1990
    Date of Patent: April 2, 1991
    Inventor: Helmut Apfel