Granted Patent
Utility
US 4,424,702 · App. 06/360,433
Device for monitoring the concentration of an air-vapor mixture
Inventor:
Holger Schoenewolf
Patented Case
View Patent ↗
Granted: Jan 10, 1984
Filed: Mar 22, 1982
Inventor
Holger Schoenewolf
Assignee (at issue)
Siemens Aktiengesellschaft
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.