Theoretical air-cylinder duration from cylinder volume, pressure, and consumption rate. Apply safety factor.
Formula
$$ t = \frac{V_\text{cyl} \cdot P}{\text{RMV}} \cdot (1 - \text{reserve}) $$
Symbol legend
| Symbol | Meaning | Unit | Source |
|---|---|---|---|
| $V_\text{cyl}$ | Cylinder water-volume | L | cylinder spec |
| $P$ | Service pressure | bar | cylinder spec |
| $RMV$ | Respiratory minute volume | L/min | observed workload |
Sources
- SOLAS II-2 Reg 10 / FSS Ch.3.
- EN 137 - Respiratory protective devices.