Sterilization Planner
Sterilization Hold Calculator
Get a hold-time recommendation based on your media type, elevation, pressure, and heat penetration behavior. The simulated curve updates live as you adjust inputs.
Thermal Profile — 197 Readings
Logged at 1-min intervals · Hold threshold: 118.3°C · Simulated from current inputs
Using estimated defaults — no logged runs yet for this equipment + media combination
Recommended Hold
111
minutes
Conservative Hold
126
minutes
Applied Temp
118.3
°C
Come-up Credit
−3
min saved vs no come-up
Calculation Summary
How your result is determined
Pressure at Your Elevation
12.24 PSI atm + 15.0 gauge = 27.24 PSI absolute
Chamber Temperature
Pressure-derived 118.3°C | Applied 118.3°C (no cap reduction)
Steam Purity Assumption
Temperature is derived from the saturation curve for pure dry steam. Residual air pockets lower the effective steam partial pressure — a 10% non-condensable gas fraction at altitude can reduce lethality rate by ~43%, requiring >2× the calculated hold time. Pre-vent your autoclave until a steady steam flow is established before sealing the weight/lid.
Gauge Pressure Sensitivity (±1 PSI)
At 4,984 ft: +1 PSI → 119.5°C | −1 PSI → 117.1°C · A 1 PSI under-read multiplies required hold by ×1.31
Consumer mechanical gauges typically carry ±1–2 PSI accuracy. Verify gauge calibration against a reference or use a digital pressure transducer.
Heat Penetration Assumptions
Grain (rye, wheat, corn, oat) | 3 lb | Preset | Lag 55 min | Tau 3.0 | Start 20.0°C
Lethality Goal
Target F₀ = 60. Steady-state hold: 114 min. Come-up credits 1.7 F₀ (3 min equivalent), leaving 110 min above threshold.
Helpful References