What this calculator does
The Nitrox Gas Blending Calculator tells scuba divers and gas blenders how much pure oxygen and how much air to add when mixing enriched air nitrox (EANx) by the partial-pressure method. Starting from an empty cylinder, you first fill with pure oxygen to a calculated pressure, then top up with air (which is 21% oxygen) until you reach your final fill pressure. The result is a cylinder holding your exact target oxygen fraction.
The formula explained
Because the total oxygen in the tank is the oxygen you add plus the 21% oxygen that comes in the air, the oxygen partial pressure needed is:
Here F_{O_2} = target oxygen fraction (for EAN32, F_{O_2}=0.32) and P_f = final fill pressure. The air added is simply the remainder:
How to use it
Enter your target oxygen percentage, your final fill pressure, and the pressure unit (psi or bar). The calculator returns the oxygen pressure for step one and the air added for step two. Add oxygen slowly, let the cylinder cool, then top with air and always analyze the final mix before diving.
Worked example
To blend EAN32 to a 3000 psi fill:
So you would add pure oxygen to about 418 psi, then top up with air to 3000 psi.
使用注意事項與精準校對原則（6 大核心守則）
📐 1. 嚴格對齊輸入量綱與單位
輸入各項數值時請務必確認量綱（例如小時、天數、金額、百分比），避免單位不匹配引發推算偏差。
🔒 2. 純前端本機毫秒級隱私保障
所有計算邏輯 100% 在您的終端瀏覽器內完成，資料絕不上傳伺服器，嚴格守護商業與個人隱私。
📊 3. 符合公認學術與產業計算模型
演算法嚴格遵循國際通用數學公式與標準計算模型，經多重情境交叉核對，數值嚴密精確。
📋 4. 一鍵複製與免登入 PDF 匯出
支援一鍵複製推算結果字串至剪貼簿，亦可直接點擊列印按鈕輸出純淨 PDF 工作報表。
🔄 5. 多情景敏感度動態對比
建議針對極端值與多組預期情景分別試算，觀察輸出數據的波動區間，輔助做出更穩健的決策。
🛡️ 6. 專業諮詢與日常參考免責聲明
本工具運算結果供日常排程、學業研習與事前參考之用，如涉及重大法規或投資決策請諮詢持證專家。