E Series
1972 - 1978
These were a mechanical top pan hybrid fitted with a Moire fringe sensors to determine the exact inclination of the beam. They had a digital display using TTL electronics
Four versions were made:
| Model | No. Made | Years |
|---|---|---|
| ETP40 | 4 | 1972 - 1975 |
| ETP41 | 1 | 1975 |
| E22TD | 5 | 1975 - 1977 |
| E32TD | 35 | 11974 - 1978 |