| Diesel | Gasoline |
Depth or Vertical Size (mm) | 31 | 42 |
Time of flight (ns) | 0.391 | 0.390 |
Dielectic permittivity ε | 3.60 | 1.95 |
Velocity (mm/ns) | 159 | 215 |
λ/4 (mm) | 19.7 | 27 |