Calculating Gas Density

[Capt Jim Wyatt]

Gas density and work of breathing (WOB) are almost directly related. The higher the density the higher the WOB. Gas density is expressed as grams/liter (g/L). High WOB increases the chances of hypercapnia, and we should not have gas density higher than 5.2 g/L.

Using the formulas shown below you can determine your gas density. In order to know the density at depth multiply surface gas density by ATA.

I used a spreadsheet to make these calculations. The integral formula is shown in the formula bar.
=(E2*B4)+(E3*B3)+(E4*B2) calculating the gas density of 18/40 at 165 fsw.

 

[BoltSnap]

Depth is in ft or m?

 

[dbulmer]

Depth is in ft or m?

I think it's feet -

He said:
I used a spreadsheet to make these calculations. The integral formula is shown in the formula bar.
=(E2*B4)+(E3*B3)+(E4*B2) calculating the gas density of 18/40 at 165 fsw.

 

[Capt Jim Wyatt]

Feet

 

[BoltSnap]

If gas density is in g/L, metric, shouldn't the depth be in metric, meters?

 

[Capt Jim Wyatt]

If gas density is in g/L, metric, shouldn't the depth be in metric, meters?

Not necessarily.

You are welcome to make a metric version.

I don't know what the imperial equivalent to g/L is. Do you?

 

[BoltSnap]

Isn't temperature a factor in the equation?

 

[Capt Jim Wyatt]

Isn't temperature a factor in the equation?

Insignificant.

 

[lostsheep]

I don't know what the imperial equivalent to g/L is. Do you?

It’s any mass per volume you want.

Microslugs per cubic furlong?

ETA: 2.90 x 10^12 microslugs / furlong ^3

 

[Deep Wreck Diver]

MultiDeco has gas density calculations as a tool with 2 different temperature settings

I prefer g/L but I believe there is also the option to use obsolete units as well