Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5144598 | Intergrating, indicating, and controlling seismometer | Paul D. Engdahl, Roger P. Engdahl | 1992-09-01 |
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5144598 | Intergrating, indicating, and controlling seismometer | Paul D. Engdahl, Roger P. Engdahl | 1992-09-01 |