Which of the following is not a valid N2 range?

• A. 95-101%
• B. 60-100.1%
• C. 103% max
• D. 101-103%

Answer: (B)

The concept being tested is how a valid nitrogen (N2) concentration range is expressed. In most gas- mixture contexts where N2 is the dominant component, the range is described around near-pure nitrogen with only small tolerance, so you’d expect values that stay close to 100% or just slightly above due to measurement or pressure effects.

The option that starts as low as 60% and goes up to just over 100% is not plausible for an N2 range because it implies a nitrogen content that can be much less than nitrogen-dominated, which contradicts the typical intent of an N2 range being near-pure nitrogen. The other ranges stay within or near the near-100% zone (with tiny allowances above 100% for measurement tolerance), so they align with how such ranges are normally defined. Therefore, the 60-100.1% range is not a valid N2 range.