A question of terminology regarding Nitrox

Is anything >21% a "mixed" gas?

  • Yes

    Votes: 42 51.2%
  • No

    Votes: 15 18.3%
  • Depends what type of system was used to "make" it.

    Votes: 0 0.0%
  • "Mixed" = Trimix --- "Blended" = >21%

    Votes: 20 24.4%
  • What he said

    Votes: 5 6.1%

  • Total voters
    82

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Father

Contributor
Scuba Instructor
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Location
Kwajalein Atoll, Marshall Islands
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Is Nitrox (EANx) a "mixed gas" if you are actually "blending" pure O2 into a compressor that produces 21%?
Is Nitrox that's "made" using a membrane system considered a "mixed" gas?

Or am I reading too much into semantics and the terminology on this is considered to be interchangeable?

Is there a different term for >40% than <40% or are they both technically mixed gasses and Nitrox?
 
Is Nitrox (EANx) a "mixed gas" if you are actually "blending" pure O2 into a compressor that produces 21%?
Is Nitrox that's "made" using a membrane system considered a "mixed" gas?

Or am I reading too much into semantics and the terminology on this is considered to be interchangeable?

Is there a different term for >40% than <40% or are they both technically mixed gasses and Nitrox?

Recreational diving I hear mix referring to anything that isn't unmodified air or oxygen. Any mixing (combining intentionally) of gasses results in a mixed gas. The method of mixing or the contents isn't important.

What about if someone makes hypoxic nitrox <21% o2?

Regards,
Cameron
 
"Mix" usually refers to having Helium in the mixture. Nitrox at any percentage is not usually referred to as mixed, but rather blended. It matters not how the blend is made (partial pressure, membrane, whatever), it is just EANx/Nitrox when it is finished. Referring to a blend when using a membrane system is more historical than accurate. Before there were membranes, and all >21% gases were made by blending O2 and air, one referred to "the blend" and that usage is still common. So if I tell you the blend in my tank is 32%, you have no way of knowing how that was produced. If I have a 50% blend or a 80%, as is common in technical/deco diving, those are almost surely done by blending O2 and air, membranes being rare (if they exist at all) for those higher percentages. >40% or <40% is a bit of a historical break-point too; and has to do with the possibility of a fire/explosion from high levels of O2. that possibility is through to be low for <40%.
 
:goodpost: @northernone
Perfectly stated. Anything containing gas that isn’t pure air/oxygen/argon or anything else you’d have in a tank is a mixed gas.
 
If it isn't air it has to be mixed by someone, 'cause it ain't natural.


Bob

I've been rumored to brew methox in my drysuit on occasion....
 
If it isn't air it has to be mixed by someone, 'cause it ain't natural. Bob
Mixed? Or blended?

"Mix" usually refers to having Helium in the mixture. Nitrox at any percentage is not usually referred to as mixed, but rather blended.

But the course to learn how to do O2 and Helium is "blender" course.
 
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