Patents by Inventor Thor G. Graeff

Thor G. Graeff 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).

  • Procedure and means for measuring radon content in the air
    Patent number: 4977318
    Abstract: A procedure and a means for measuring radon content in the air, in which procedure the radon content in the air is measured by measuring the ion content of the air caused by the radon in the air and by its decay products.
    Type: Grant
    Filed: August 3, 1989
    Date of Patent: December 11, 1990
    Assignee: Ilmasti Elektroniikka Oy
    Inventors: Veikko Ilmasti, Thor G. Graeff