Dräger SCBA Air Time Calculator
Select a model, choose your cylinder, enter pressure and breathing rate — duration is calculated instantly.
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ReadyDräger SCBA Air Time Calculator – PSS 7000, PSS 5000, PSS 4000, PSS 3000
Dräger's PSS series (Pressluftatmer, meaning compressed-air breathing apparatus) covers four current generations designed for different operational requirements and budget profiles. The PSS 7000 is the flagship with full electronics; the PSS 3000 is the entry configuration without HUD or integrated PASS. All share the same air calculation logic — cylinder water volume multiplied by usable pressure — but differ in weight, electronics, and NFPA availability. Select the exact PSS model to match the cylinder and pressure options available for your unit.
PSS 7000 vs PSS 5000 vs PSS 4000 vs PSS 3000: what changes
The PSS 7000 is Dräger's full-featured model: integrated HUD, integrated PASS, and dual certification capability (EN 137 Type 2 and NFPA 1981 in some configurations). The PSS 5000 adds HUD and PASS but at a lower price point. The PSS 4000 drops the HUD. The PSS 3000 has no HUD and no integrated PASS. Air capacity and cylinder options are similar across models — the differences are electronics, harness options, and certification scope. This affects operational capability, not basic air volume.
EN 137 vs NFPA 1981 on Dräger PSS units
Some Dräger PSS 7000 configurations can be ordered with dual certification (EN 137 Type 2 and NFPA 1981), but this requires specific cylinder types and electronics packages. The standard European PSS 7000 is EN 137 Type 2 only. If your department procured NFPA-certified PSS units, confirm the cylinder operating pressure and reserve with your Dräger datasheet — NFPA configurations may operate at different pressure ratings than the EN standard 300 bar.
Dräger cylinder options: 221 bar steel vs 300 bar carbon
Dräger PSS cylinders are available in both 221 bar steel and 300 bar carbon fibre configurations. The 221 bar steel cylinder is older technology and provides less air per kilogram of cylinder weight, but is still in service at many departments. The 300 bar carbon cylinder is lighter and holds more air at equivalent water volume. When calculating air time, selecting the correct service pressure matters — a 6.8L cylinder at 221 bar holds significantly less air than the same volume at 300 bar.
Dräger alarm signals and reserve: matching your SOP
Dräger PSS units equipped with electronics typically provide audio/visual warnings at defined pressure thresholds. The low-pressure alarm is set by the manufacturer to comply with EN 137 requirements, but your department's operational reserve policy may be different from the alarm trigger point. Always enter your department's required reserve pressure in this calculator, not the alarm trigger value — they are not always the same number.
Why two firefighters with identical PSS units get different times
Same PSS model, same cylinder, same starting pressure — but actual air time varies by individual. The primary driver is RMV (Respiratory Minute Volume), which depends on fitness level, heat adaptation, stress response, task intensity, and mask seal. A well-fitted, trained firefighter in moderate conditions may breathe at 35–40 L/min. The same person in high heat during victim rescue may exceed 70 L/min. Use this calculator with your department's measured RMV data where available.
FAQ
Notes & Safety
This is an estimate based on the values you enter. Real-world air consumption changes with workload, stress, temperature, mask seal, leaks, and individual physiology. Always follow your SOPs and monitor your pressure gauge continuously.