RINA’s underwater-radiated-noise (URN) notation - aligned with IMO MEPC.1/Circ.906 and ABS UWN.
Formula
$$ \text{URN}\text{measured} \leq \text{Limit}\text{category} $$
Symbol legend
| Symbol | Meaning | Unit | Source |
|---|---|---|---|
| $URN$ | Underwater radiated noise | dB re 1 μPa at 1 m | ISO 17208-1 test |
Sources
- IMO MEPC.1/Circ.906 - URN guidelines.
- ISO 17208 - URN measurement.