Patents by Inventor Douglas Stuart Thompson

Douglas Stuart Thompson 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).

  • Spectrophotometric formaldehyde-copper monitor
    Patent number: 3951602
    Abstract: In an apparatus comprising a spectrophotometer, an inspection cell, and an electroless copper plating bath containing copper ions and formaldehyde for measuring the copper ion concentration of the bath spectrophotometrically, the improvement which comprises method and apparatus for spectrophotometrically measuring the formaldehyde concentration of the bath. The improved apparatus includes a source of reagent reactive with formaldehyde and a reaction vessel, useful for reacting the reagent with formaldehyde to produce a reaction product photoindicative of formaldehyde concentration.
    Type: Grant
    Filed: June 25, 1974
    Date of Patent: April 20, 1976
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Douglas Stuart Thompson