Ok, maybe I am not the sharpest knife in the drawer, so what am I missing here.....
On pg 37 of his 4th edition, he does a bunch of calculations to determine a gas mix for the Doria.
While he states the operation incorrectly, he computes total pressure at 240 fsw as 8.27 ata and then divides 1.4 ata (target Po2) by 8.27 ata x 100% for 17% (which I am assuming is the FO2)
He then computes target N2 for a 100 fsw END by
100 fsw
------- + 1 = 4.03 ata
33 fsw
PN2= .78 x 4.03 ata = 3.14 ATA
3.14 ata
-------- = .38 or 38%
8.27 ata
So, I think at this point, the FO2 is 17%, the FN2 is 38 percent. However, in the paragraph after all of the calculations, he states
"If the PO2 is 17%, and the FO2 is 38%, then the balance of the mix, 45%, will be He. So the answer is a 19/45/38 trimix (or a 19/45 as such mixes are usually referred to, omitting the FN2)."
Should it not have been...
"If the FO2 is 17%, and the FN2 is 38%, then the balance of the mix, 45%, will be He. So the answer is 17/45/38 trimix...."
If there weren't so many differences in what I thought it should be versus what it states, I would have just assumed they were typos.....am I missing something?
On pg 37 of his 4th edition, he does a bunch of calculations to determine a gas mix for the Doria.
While he states the operation incorrectly, he computes total pressure at 240 fsw as 8.27 ata and then divides 1.4 ata (target Po2) by 8.27 ata x 100% for 17% (which I am assuming is the FO2)
He then computes target N2 for a 100 fsw END by
100 fsw
------- + 1 = 4.03 ata
33 fsw
PN2= .78 x 4.03 ata = 3.14 ATA
3.14 ata
-------- = .38 or 38%
8.27 ata
So, I think at this point, the FO2 is 17%, the FN2 is 38 percent. However, in the paragraph after all of the calculations, he states
"If the PO2 is 17%, and the FO2 is 38%, then the balance of the mix, 45%, will be He. So the answer is a 19/45/38 trimix (or a 19/45 as such mixes are usually referred to, omitting the FN2)."
Should it not have been...
"If the FO2 is 17%, and the FN2 is 38%, then the balance of the mix, 45%, will be He. So the answer is 17/45/38 trimix...."
If there weren't so many differences in what I thought it should be versus what it states, I would have just assumed they were typos.....am I missing something?