Issued Patents 1989
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4846970 | Cross-flow filtration membrane test unit | Douglas L. Olsen | 1989-07-11 |
| 4839037 | Tapered, spirally wound filter cartridge and method of making same | David John Paulson | 1989-06-13 |