Calculating air consumption SAC / SCR / RMV

[roakey]

Originally posted by Fishkiller

If it takes me x time to empty a 40cf tank at 3000psi then it should take me the twice the amount of time to empty a 80cf in 30 feet of water...

Actually you bring up a good point. Try and use a smaller cylinder and/or do your test deep. The more "swing" you can get out of your SPG the more accurate your calculation since SPGs don't have lab-level accuracy.

I did my test with an AL40 slung as a stage to get my "hang SAC" and an LP104 at about 60' for my swimming SAC. One of these days I'll do my swimming SAC over again using a smaller cylinder.

As for AL80s not holding 80cf, I don't know who to believe anymore. Luxfer's AL80 doesn't hold the same amount of air as Catalina's AL80. Both numbers are suspect since they're from the manufacturers, whose marketing departments appear to be on drugs at times, like publishing impossible swing weights (full-to-empty buoyancy change).

You cylinder swings one pound for about every 13 cf of air you pump into it, no matter what the material, size, pressure or displacement. From manufacturer information I've seen claims of swing weights of a couple pounds for 100s. Sorry, 100s swing almost 8 pounds, period!

But I digress.

Roak

 

[Butch103]

......welcome to the darkside!!! HeHeHeHe

Butch eace:

 

[Fishkiller]

Well have to go get wet but, I say but, what about the original question? What are your Air consumption rates??

The PSI is a non-accurate methodbut it is a method, What are yours with the Walter/Warhammer method??

 

[ScubaBaby]

Walter.....ermmm....i started getting confused from the word walter and then it ended at the end of the post!!

Butch, the darkside!? I'm only a baby, i get scared of the dark!

Scubabunny....great popcorn!!!

 

[100days-a-year]

FK,Working or bottom SAC rate is .50-.60 or less.My deco SAC rate runs .35 to .50.They all depend on workload,temperature and the "adrenaline factor"Try distance running or cycling to decrease your air consumtion.

 

[Butch103]

...don't be scared (evil) hehe, :devilish: if you get scared I will hold your hand.

But what I really want to know is do you understand it yet???


Or still just gonna use the green, yellow and red on the old pressure gauge??

Butch eace:

 

[BigDiver]

I am wondering what everyones surface air consumption rates are.
Mine is not the greatest, but I am always working on it.
It is about .9 cu. ft. per min.

What is yours?

BigDiver

 

[BigDiver]

I forgot to say that I am diving in 42F water and am a realitivly new diver compared to some of the divers on this board.

 

[Jonathan]

what does it matter - just carry enough air....

for the record between 15 & 20 l/min depending on conditions, how much I've done recently etc

 

[BigDiver]

I think you know the importance of your SAC.

Sometimes there is a limit to the gas available.