Granted Patent
Utility
US 6,313,638 · App. 09/271,612
Dual-channel photo-ionization detector that eliminates the effect of ultraviolet intensity on concentration measurements
Inventors:
Hong T. Sun, Peter Hsi
Patented Case
View Patent ↗
Granted: Nov 6, 2001
Filed: Mar 17, 1999
Inventors
Hong T. Sun
Peter Hsi
Assignee (at issue)
RAE SYSTEMS, 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.