Granted Patent
Utility
US 5,447,053 · App. 08/150,142
Method and device for measuring quantities of impurities in special gas
Inventor:
Tadahiro Ohmi
Patented Case
View Patent ↗
Granted: Sep 5, 1995
Filed: Jan 31, 1994
Inventor
Tadahiro Ohmi
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.