Granted Patent
Utility
US 6,344,798 · App. 09/842,636
Using carbon dioxide to indicate oxygen depletion
Inventor:
Michael Schell
Patented Case
View Patent ↗
Granted: Feb 5, 2002
Filed: Apr 27, 2001
Inventor
Michael Schell
Assignee (at issue)
Edwards Systems Technology, Inc.
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.