Granted Patent
Utility
US 4,328,420 · App. 06/173,217
Tandem mass spectrometer with open structure AC-only rod sections, and method of operating a mass spectrometer system
Inventor:
John B. French
Patented Case
View Patent ↗
Granted: May 4, 1982
Filed: Jul 28, 1980
Inventor
John B. French
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.