ATA vs ATM which is right? Need to know for magazine.

[paperdesk]

Either is correct, has the concept of atmospheres absolute been introduced? If it has, use ATA, if it hasn't, use ATM. .

We are talking about total pressure, though it doesn't go into great depth (lol) on the topic.

Ted

 

[TwoBitTxn]

If it's a non-technical article geared towards non divers most of your readers will not understand the difference between ATA and ATM. I think ATM shold be used. If the majority of the readers are divers, there is the possibility that ATA will be understood.

Naturally, any abbreviation should be defined before being used...

 

[paperdesk]

ATA is unambigous. It is atmospheres absolute.

ATM has some possiblity of confusion. Personally, when I use ATM I mean gauge pressure, with sea level atmosphere as the reference. In other words, at 33feet you have a pressure of 1ATM and 2ATA.

Not everybody uses that convention as the meaning of ATM, but everyone agrees that ATA is an absolute pressure, referenced to vacuum. If you use ATA you eliminate the confusion.

Ok! That does make perfect sense. I'll change it to ATA.

Thank you all for your help! I'm sure I studies this when I got my c-card, but since then it's slipped into a dark place in my mind that I couldn't access . . . .

 

[paperdesk]

If it's a non-technical article geared towards non divers most of your readers will not understand the difference between ATA and ATM. I think ATM shold be used. If the majority of the readers are divers, there is the possibility that ATA will be understood.

Naturally, any abbreviation should be defined before being used...

Ohhhhh. Just when I thought I had an answer . . .

 

[300bar]

Just change the whole thing to BAR.Add 1 for atmosphere and your ready.

 

[Walter]

If you're not explaining, I would spell it out - atmospheres absolute.

 

[scubajcf]

Further referenced in the US Navy Dive Manual.

Click here to download version 6 - SEA 00C3 Diving Publications and Technical Documentation or directly at http://www.supsalv.org/pdf/DiveMan_rev6.pdf

Chapter 2 Section 2-9(1) or pages 131 and 132

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[Doc Intrepid]

Just FWIW, I agree that if the article is intended to be read by divers, I would use ATA.

Since you must define either, ATA is a more frequently used variable when calculating mixed gas diving requirements and consumption in general.

JMHO,

Doc

 

[paperdesk]

300Bar, I had the same temptation . . .

SCUBAjcf, I'm checking out the link.

How's this? Trying to keep it simple:

"At sea level, the pressure is 1 ATA (atmospheres absolute). At 33 feet below the surface, the pressure is 2 ATA." etc.

 

[Doc Intrepid]

works for me!