DISCLAIMER

IMPORTANT: This is published under the MIT licence, and the authors, owners and publishers of this library take NO RESPONSIBILITY for the risks it's uses impose.

When diving and mixing gas it's always important to use ones own knowledge and thinking to make sure things are set correctly.

Using the wrong gas mixture at the wrong depth be fatal. If the numbers seem off, double check and report it. Blending diving gases incorrectly can also be fatal. An incorrect mix may kill its user. ALWAYS measure the gas that is mixed.

• DO NOT Use this to dive with mixtures with which you have no training otherwise.
• DO NOT Use this to mix gases without proper blender-training.
• DO Forward these warnings if you ever build an app using this library

Usage

gas-limits

This can be used to calculate the maximum operational depth (MOD) and maximum narcotic depth (MND) for a given mixture of oxygen, nitrogen and helium. By default, the nitrogen-fraction is set to whatever fraction is left after oxygen and helium.

Basic usage:

const limits = calculateGasLimits({oxygen: 0.21});
console.log(limits.maxNarcoticDepthMeters) // 30
console.log(limits.maxNarcoticDepthAta) // 4
console.log(limits.maxOperationalDepthMeters) // 56.67
console.log(limits.maxOperationalDepthAta) // 6.667

Use helium for a trimix-dive

const limits = calculateGasLimits({oxygen: 0.21, helium: 0.35});

Use a more conservative ppO2 for a deco-dive bottom-phase

const limits = calculateGasLimits({oxygen: 0.21}, {maxPPO2: 1.2});

Use a more aggressive ppO2 for a deco-dive deco-phase

const limits = calculateGasLimits({oxygen: 0.21}, {maxPPO2: 1.6});

Assume oxygen is not narcotic

const limits = calculateGasLimits({oxygen: 0.21}, {oxygenIsNarcotic: false});
// Note: Default is true, as this is the most convervative option

gas-blender

This can be used to calculate the setpoints to use when mixing a new gas using an inline blender. Here you input your current mix and pressure, and the desired mix and pressure. Then you will get the percentages of oxygen and helium you need to achieve that mix.

Basic usage

const result = calculateBlenderSettings({
    fillPressureBar: 90,
    oxygenFraction: 0.21, //Air
}, {
    fillPressureBar: 232,
    oxygenFraction: 0.32, // Nitrox 32
})

console.log(result.oxygenSetpoint) //39

Trimix blending

const result = calculateBlenderSettings({
    fillPressureBar: 100,
    oxygenFraction: 0.32, // Nitrox 32
}, {
    // Trimix 21
    fillPressureBar: 232,    
    oxygenFraction: 0.21,
    heliumFraction: 0.35, 
})

console.log(result.oxygenSetpoint) //12.7
console.log(result.heliumSetpoint) //61.5