Gas Blending Calculators – Nitrox, Trimix & Custom Mix Tools

Gas Blending Calculators – Nitrox & Trimix

These tools support basic partial pressure gas blending (氣體調配) for nitrox and trimix in bar. They are intended for qualified gas blenders and technicians and assume proper training in gas blending (氣體混合) and compressor operations.

  • Nitrox blending: current mix, target mix, O₂ + air top-up
  • Trimix blending: current mix, target mix, choice of O₂-first or He-first partial pressure sequence
  • Top-up with non-air gas: predict final mix when topping with any custom gas

Nitrox Blending – O₂ + Air Top-Up

This calculator assumes standard partial pressure blending: first add pure oxygen (100% O₂), then top up with air (21% O₂ / 79% N₂). It tells you how many bar of oxygen to add, and then how many bar of air to reach the target mix.

Result will appear here.

If the current mix already has higher O₂ than the target, or the requested target cannot be reached by adding O₂ then air, the tool will warn that the blend is not achievable without venting or using a different method.

Trimix Blending – Partial Pressure O₂ / He + Air

This calculator assumes partial pressure blending (分壓混氣) with pure oxygen and pure helium: you choose whether to fill oxygen first or helium first, then finish with air. It outputs how many bar of O₂, how many bar of He, and how many bar of air to add.

Result will appear here.

Assumes: first gas is pure (100% O₂ or 100% He), then air (21% O₂, 0% He). If required pressures are negative or out of order, the target mix is not achievable with this simple sequence.

Top-Up with Non-Air Gas – Final Mix Calculator

This tool calculates the final mix when you top up a cylinder with any custom gas, such as a banked nitrox, helitrox or trimix blend.

Result will appear here.

Assumes ideal mixing and topping from current pressure directly up to target pressure with the specified top-up gas. Final nitrogen fraction is computed as 1 − O₂ − He.

Safety notice: These tools are for trained gas blenders only. They assume ideal gas behaviour, accurate gauges and correct analysis. Always verify final mixes with a calibrated analyser and follow relevant standards and agency procedures. Never blend gases beyond your training or legal requirements.