Granted Patent
Utility
US 6,790,666 · App. 10/209,347
Method to ascertain whether soluble hardness is calcium or magnesium based
Inventors:
Xiaojun Dang, David A. Grattan, Linda Link
Patented Case
View Patent ↗
Granted: Sep 14, 2004
Filed: Jul 31, 2002
Inventors
Xiaojun Dang
David A. Grattan
Linda Link
Assignee (at issue)
Nalco Company LLC
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.