| to allow controllable altitude profiles | 3 | purpose |
| in the thermal envelope | 2 | location |
| balloon → have → valve | 4 |
| balloon → use → valve | 4 |
| balloon → deliver → new valve | 3 |
| negative | neutral | positive |
| 0.055 | 0.852 | 0.094 |
| Raw frequency | 11 |
| Normalized frequency | 0.207 |
| Modifier score | 0.500 |
| Perplexity | 309.332 |