| Etching time (min) | Track density (no/mm2) | Time of exposure to alpha source | |
| (10 sec) | (20 sec) | (30 sec) | |
| 30 | 614 | 1212 | 1672 |
| 60 | 658 | 1271 | 1874 |
| 90 | 689 | 1267 | 2067.9 |
| 120 | 757 | 1345 | 1975 |
| 150 | 640 | 1265 | 1814 |
| 180 | 672 | 1255 | 1790 |
| 210 | 662 | 1204 | 1778 |
| 240 | 638 | 1088 | 1721 |
| Average | 666.2 | 1239.5 | 1836.48 |
| Max | 757 | 1267 | 2067.9 |