Average Gas Consumption

[scubadada]

Maybe someone will help me understand the SAC Rate my Aeris XR2 download program calculates. Here's the info from dive #257 in 78 degree water:

I was wearing a non-neoprene Sharkskin suit with 6 lbs. of lead.

Cylinder: Faber Steel 80
Working Pressure: 3500 PSI
Dive Time: 53 minutes
Average Depth: 62.17 FT
Start Pressure: 3700 PSI
End Pressure: 800 PSI
FO2: 36%
SAC Rate: 0.015 FT3/min. (the 3 is in very small print next to the top right side of the T)

I've gone to the Aeris manual and can't find the info I need.

So, is my SAC Rate good or bad? And which answer would I put in the survey? That is the question.

Hi islanddream,

I did not think the Aeris XR2 was an AI computer, are you sure that is the model you are using? Assuming you are using a Pelagic Pressure Systems computer (Oceanic, Aeris before being merged into Oceanic), are you using the OceanLog download software or some other application? I currently dive an Oceanic VT3 and am using OceanLog 2.4.9, 6/12/15. In the dive log are listed cylinder size, working pressure, dive time, average depth, start pressure, and end pressure. The application calculates SAC in psi/min and RMV in cu ft/min. As an example, for a recent dive with an AL80, I had a SAC of 14 psi/min and a RMV of 0.36 cu ft/min.

I have no idea what the 0.015 cu ft/min in your log is. There are simple calculators you can use to generate your RMV such as DiveNerd - SAC Rate / RMV Calculator, Imperial Units Using this calculater, your RMV appears to be 0.43 cu ft/min. You would use that to vote in the poll assuming that is around your average RMV. Best of luck figuring out your download software.

Good diving, Craig

 

[Doby45]

I got my AVG SAC from Subsurface..

 

[gopbroek]

I got my AVG SAC from Subsurface..

View attachment 377049

I am probable wrong but I have always thought that the # Subsurface calculates as 'SAC' was really an 'RMV' calculation (which to me is a much more usefull value)

 

[Doby45]

I believe you are correct. I also referenced @NWGratefulDiver webpage that he explains this stuff on.

NWGratefulDiver.com

 

[islanddream]

Hi islanddream,

I did not think the Aeris XR2 was an AI computer, are you sure that is the model you are using? Assuming you are using a Pelagic Pressure Systems computer (Oceanic, Aeris before being merged into Oceanic), are you using the OceanLog download software or some other application? I currently dive an Oceanic VT3 and am using OceanLog 2.4.9, 6/12/15. In the dive log are listed cylinder size, working pressure, dive time, average depth, start pressure, and end pressure. The application calculates SAC in psi/min and RMV in cu ft/min. As an example, for a recent dive with an AL80, I had a SAC of 14 psi/min and a RMV of 0.36 cu ft/min.

I have no idea what the 0.015 cu ft/min in your log is. There are simple calculators you can use to generate your RMV such as DiveNerd - SAC Rate / RMV Calculator, Imperial Units Using this calculater, your RMV appears to be 0.43 cu ft/min. You would use that to vote in the poll assuming that is around your average RMV. Best of luck figuring out your download software.

Good diving, Craig

Hi Craig:

Thanks for the info. My Aeris XR2 isn't an AI computer. I use the logbook provided by Aeris and it automatically puts in DC Model: XR2. After your post, I edited mine to show info that I get when using an AL80. These numbers make much more sense.

 

[islanddream]

OK...with a little more research I found I had the cylinder size incorrect. I've now put in the right size (78.2 FT3) and my SAC rate makes much more sense!

 

[scubadada]

I believe you are correct. I also referenced @NWGratefulDiver webpage that he explains this stuff on.

NWGratefulDiver.com

This is nicely written, I have read it several times

 

[scubadada]

Interesting results, nice normal distribution. Please vote if you have not participated.

 

[beester]

To be honest... no ***** given when it comes to my average gas consumption. Because it can be anything from 12L/min to 18-19L/min.

 

[scubadada]

To be honest... no ***** given when it comes to my average gas consumption. Because it can be anything from 12L/min to 18-19L/min.

and, hopefully, you will submit your average to the poll, see conversion p 4 of thread for metric to imperial. I'm sorry I didn't include the conversion in the original poll, hindsight....