Scuba Diving International (SDI) Computer Nitrox Practice Exam

What is the acceptable range of accuracy blenders must adhere to for a given Nitrox mixture with a particular FO2?

1. 5%

2. 2%

3. 1%

4. 0.5%

The correct answer is: 1%

Blenders must ensure that the Nitrox mixture produced meets stringent accuracy requirements to maintain safe and effective diving practices. The acceptable range of accuracy for blenders when preparing a specific Nitrox mixture with a defined fraction of oxygen (FO2) is established at 1%. This means that the actual oxygen content in the blended gas should not deviate more than 1% from the target FO2 level. This high level of precision is critical because even small variations in the oxygen percentage can significantly impact a diver’s exposure to nitrogen and oxygen, potentially leading to oxygen toxicity or insufficient safe breathing gas mixtures at certain depths. The commitment to a 1% accuracy standard reflects the industry's focus on safety, allowing divers to plan their dives confidently, knowing the breathing gas they are using is precisely what they expect. Other choices, while they represent various levels of acceptable accuracy, do not meet the stringent requirements set by organizations concerned with diver safety and gas blending, which is why only the 1% standard is recognized as acceptable in this context.