Issued Patents All Time
Showing 1–4 of 4 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 6321604 | Electro-optical float position indicator | Donald C. Frick, Wayne D. Tessarvich | 2001-11-27 |
| D292891 | Manometer | Donald C. Frick | 1987-11-24 |
| 4479377 | Method and apparatus for measuring gas flow | Donald C. Frick | 1984-10-30 |
| 4307601 | Apparatus for calibrating flow meters and the like | — | 1981-12-29 |