| Pressure | Natural Frequency fd, Hz | ||||
| kPa | 1st trial | 2nd trial | 3rd trial | 4th trial | 5th trial |
| 101 (Atm*) | 130 | 129 | 130 | 130 | 130 |
| 81 | 148 | 148 | 149 | 148 | 148 |
| 54 | 160 | 160 | 160 | 161 | 160 |
| 27 | 190 | 191 | 190 | 190 | 190 |
| 13 (Base)+ | 211 | 210 | 211 | 209 | 211 |