Issued Patents 1989
Showing 1–1 of 1 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4837509 | Method and apparatus for measuring diameter of a steel reinforcement rod embedded in concrete and the thickness of the concrete overlayer | Otto Kroggel, Jochen Fey, Harald Kopp, Christoph Fritz | 1989-06-06 |