36 replies to this topic

[PerroneFord]

Here you go miss cranky pants:

Air is the most common and only natural breathing gas. Other artificial gases, either pure gases or mixtures of gases, are used in breathing equipment and enclosed habitats such as SCUBA equipment, surface supplied diving equipment, recompression chambers, submarines, space suits, spacecraft and anaesthetic machines.

Most breathing gases are a mixture of oxygen and one or more inert gases. All breathing gases are alternatives to air and have been developed to improve on the performance of air by reducing the risk of decompression sickness, reducing the duration of decompression stops, reducing nitrogen narcosis or allowing safer deep diving.

A safe breathing gas has three essential features:

it must contain sufficient oxygen to support the life, consciousness and work rate of the breather.
it must not contain harmful gases. Carbon monoxide and carbon dioxide are common poisons in breathing gases. There are many others.
it must not become toxic when being breathed at high pressure such as when underwater. Oxygen and nitrogen are examples of gases that become toxic under pressure.
The techniques used to fill diving cylinders with gases other than air are called gas blending.

[source: Wikipedia, the free dictionary]

[Dive_Girl]

Are you getting paid by the thread or something?

Sure, I'll be happy to post why I don't use air.

Dangit! You found me out! Actually, maybe it's the instructor in me, but organizing topics by threads creates a useful user-friendly resource of diving information. It goes hand-in-hand with what we are hoping to see grow from this forum!

[Walter]

Sure, I'll be happy to post why I don't use air.

Please do.

[Dive_Girl]

Sure, I'll be happy to post why I don't use air.

Please do.

The discussion of air/gas, what to use for diving, has been split off to start a new topic here.

[peterbj7]

Semantics can get rather silly. As a Brit I've already had to get used to American, but I have no problem with alternative words so long as there's no doubt, confusion or ambiguity. Often there isn't. Certainly "mask" and "goggles" are different and the words shouldn't be substituted. "Flippers" is fine. I actually often use the word "air" when I mean "breathing gas" when the nature of the gas concerned is not material to the issue at hand - it's shorter and more immediately understood.

I'd better go and read the air-gas thread.

[jextract]

Semantics can get rather silly. As a Brit I've already had to get used to American, but I have no problem with alternative words so long as there's no doubt, confusion or ambiguity. Often there isn't. ...

No kidding. Next thing you know, people will be putting useless 'u's in words, like colour and labour.

[6Gill]

::Miss Cranky Pants ON

You put AIR in your tanks... You put GAS in your car...You get GAS when you eat beans..... I don't care if it's 21% 32% 36% heilum, or whatever it's still AIR.....

In any definition of GAS I cannot find it talking about AIR we BREATHE.

Most things exsist as solid,liquid or gas.What you put in your car is gasoline a liquid not a gas.The British fill with petrol(shorten the word petrolum)

No kidding. Next thing you know, people will be putting useless 'u's in words, like colour and labour.

You mean they continue to spell correctly It's intresting how Webster shortened(changed the spelling) a number of words but not all new spellings caught on.

[Walter]

::Miss Cranky Pants ON

You put AIR in your tanks... You put GAS in your car...You get GAS when you eat beans..... I don't care if it's 21% 32% 36% heilum, or whatever it's still AIR.....

In any definition of GAS I cannot find it talking about AIR we BREATHE.

Most things exsist as solid,liquid or gas.What you put in your car is gasoline a liquid not a gas.The British fill with petrol(shorten the word petrolum)

No kidding. Next thing you know, people will be putting useless 'u's in words, like colour and labour.

You mean they continue to spell correctly It's intresting how Webster shortened(changed the spelling) a number of words but not all new spellings caught on.

Actually, at the time Webster lived, spelling was not uniform anywhere in the English speaking world. There were no misspelled words because there were no agreed upon correct ways to spell. He didn't shorten (change the spelling) a number of words. When spelling became set, it happened differently in different places.

[cmt489]

Semantics can get rather silly. As a Brit I've already had to get used to American, but I have no problem with alternative words so long as there's no doubt, confusion or ambiguity. Often there isn't. ...

No kidding. Next thing you know, people will be putting useless 'u's in words, like colour and labour.

Just because some of us wish to keep the integrity of the English language alive...

[hnladue]

The measures of gas that are used are cubic feet or litres, with around 28 of the latter to one of the former. "Surface Air Consumption" or SAC is given based on either of these units, so you can see that SAC doesn't mean a lot unless you know how much gas you're carrying.

If it's Surface AIR Consumption doesn't that mean AIR???? It doesn't say Surface GAS Consumption.... So does that mean that Perrone doens't have a SAC? oh what.... that came out all wrong... oops! (just kidding Perrone! XXOO)

Just trying to make a point (badly) that we should stick to AIR not GAS as most of the newbies are taught AIR... just like the in the calculations we do... Surface Air Consumption.... When someone says to me Gas I automatically think gasoline.. It could confuse new people.

[click here for a discussion on air/gas]

[PerroneFord]

The measures of gas that are used are cubic feet or litres, with around 28 of the latter to one of the former. "Surface Air Consumption" or SAC is given based on either of these units, so you can see that SAC doesn't mean a lot unless you know how much gas you're carrying.

If it's Surface AIR Consumption doesn't that mean AIR???? It doesn't say Surface GAS Consumption.... So does that mean that Perrone doens't have a SAC? oh what.... that came out all wrong... oops! (just kidding Perrone! XXOO)

Just trying to make a point (badly) that we should stick to AIR not GAS as most of the newbies are taught AIR... just like the in the calculations we do... Surface Air Consumption.... When someone says to me Gas I automatically think gasoline.. It could confuse new people.

It's surface AIR consumption because it's relative to the air we breathe on the surface. Has nothing to do with what we breathe underwater. But do note that we tend to speak in RMV instead of SAC, so we can relate tanks instead of surface consumption rates...

As for the personal comment about my SAC, well, I'll only say it's no more odd than you HAVING one!

[Dennis]

Did we sufficiently hijack this thread or what? From what do you call your fins/flippers, to tank inspections.

[Dive_Girl]

Did we sufficiently hijack this thread or what? From what do you call your fins/flippers, to tank inspections.

I didn't realize how many posts were discussing working pressures and tanks! Excellent discussion though and holy moly I am learning LOTS - so I moved them into their own thread here.

[Capn Jack]

Did we sufficiently hijack this thread or what? From what do you call your fins/flippers, to tank inspections.

I'm ok with where we've been - we've split a couple of topics off - the discussion I think is continuing to travel down the road of precision and accuracy of communications.

Geographies and communities tend to create their own lingo of diving - but some terms need clarity or at least understanding.

What I'm hoping to see is more discussion, more learning.

"play on"

[Dive_Girl]

Tanks, bottles, cylinders - in regards to SCUBA are they all synonomous - are they all accurate - is one better than the other?