Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5674401 | Oil monitor with magnetic field | James F. Kirkpatrick, Eric Johnson, Keith A. Hawn | 1997-10-07 |
| 5614830 | Oil monitor with magnetic field | James F. Kirkpatrick, Eric Johnson, Keith A. Hawn | 1997-03-25 |
| 5262732 | Oil monitor with magnetic field | Eric Johnson, James F. Kirkpatrick, Keith A. Hawn | 1993-11-16 |