Granted Patent
Utility
US 4,890,490 · App. 07/205,829
Liquid level monitoring
Inventor:
David Telford
Patented Case
View Patent ↗
Granted: Jan 2, 1990
Filed: Jun 13, 1988
Inventor
David Telford
Assignee (at issue)
United Kingdom Atomic Energy Authority
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.