Different pp02?

[sdol]

Hi all.

I'm a happy new owner of a 2N. It really is a great piece of equipment.

Anyway i would like to ask a question.

I dive OC, bottom mix 1,4 ppo2, deco gas 1,6 ppo2.
I was changing the CF settings of the 2n and i see that if i put the CF18 on 1,4 ppo2 then the MOD for air, nitrox and tirmix is calculated OK, but for deco gas (nitrox 50%) don't allowd me to change only for this gas the value of ppo2.
When i ascent on -21m i want to change the gas in the gaslist is my deco gas red, because is over my limit. Any suggestions?

Another thing...what is the CF46? I don't understand the difference between them.

Thank for the answer.
Regards.
S

[Bardass]

No, there is only one parameter for PPO2
but you can change MOD for each mix that you have entered in your list

CF46 is the value of ppO2 from which you want to be warned (with the color of warning CF37)

[Solodiver]

Have U tried to change the depth in the gas settings?

Regarding the CF questions I assume this:
CF18 is for displaying the ppO2 (at all, not displayed before this treshhold), CF46 is for displaying the (already shown) ppO2 in red

HTH,
Jan

[sdol]

Hi.

Yes, I set the depth for deco gas, but when i want to change gas at 21m from TX to NX in the gas list NX50 is red. If i put CF37 on 1,6 the red colour won't warn me that i exceded the 1,4 with TX at the bottom.

Had anybne the same problem and how did you resolve it?

Regards.
S

[sdol]

Now i'm worried...no one dives like me?
Don't you change deco gas 50% nx at 21m?

[heinrichsweikamp]

Hi,

I think most of us dive like this. But, besides the ppo2 getting red there is no negative effect with the way it is now.

regards,
Matthias

[sdol]

True, but evertime when i try to change gas on 21m and i open the gasmenu i see the red deco gas and i ask myself what i'm doing wrong. It's not negative effect but is annoying.
I thnik that in the gas menu set list it should be an option deco gas which it allowd the partial to be max 1.6 after it turns the colour as it is imposted in CF46.
It's only my opinion. I was hoping that there is a way aorrund.
Regards
Sdol

[PeterK]

I have my unit set to max ppO2 1.6. I control the ppO2 of my bottom gas during dive planning rather than the OSTC. Therefore, I never had a problem with this issue.

I'm quite sure that you do the same. First you select your max depth. Then you calculate either the best mix with your desired ppO2 at target depth or you pick an appropriate standard mix (e.g. 21/35 or 18/45) meeting your needs.

Sticking to your plan rather than relying on a warning on your dive computer is a good idea in my opinion.

This is not ment as an offense.

[sdol]

I've take the other approach...i set up the max ppO2 on 1.4 not beacuse of the warning at the deep, but because of feature calculating MOD in the gas list. I think it's a great feature and if you dive air or nx (without deco bottle) this feature is lost when ppO2 is set to 1.6.
As i said, in my opinion it's very little change to do in the gas set list to do and it will be all working as it should.
Regards,
Sdol

[PeterK]

Well, why dont you set the max ppO2 to 1.4? As said before the depth for changing is set separately for each gas, no matter what you've selected as max. ppO2.

[sdol]

And as i said before i'm usig it 1.4 now. When io reach 21m for gas changefrom tx to nx50, open the gaslist the nx50 is red. As something is wrong (is the first think you would think about). It has no negative effect but is very annoying.
If the developers thinks that a simple solution can be done i'm asking it for the next stable release.
Regards.
Sdol

[Mornemont]

My 2 cents: NX50 @ 21m = 50% * 3.1 bar = 1.55 bar. If the limit is set to 1.4, the PPO2 must get red whent you change. Am I missing something?

F

[sdol]

Yes, that's the problem, because if i understand right you can't choose different ppO2 or the warning colour for each gas.

[Rebel]

I also would like to see a seperate setting for PP02 for each gas. Also what is the point of having a computer if your going to solely rely on the plan? I would like my computer to match my plan, then dive of the computer with the plan as my back-up (if computer fails).

[Voss]

Maybe I'm misreading the original question, but as far as setting different PPO2 for back and deco gases are concerned this might help:

http://www.heinrichsweikamp.com/read.ph ... 7#msg-5407

[scubatinoo]

@sdol:

i don't understand your point. With CF17 and CF18 you set a range of allowed ppO2 between 0.19 and 1.6 bar. That's a normal range every tec-rec diver is sticking on... Below or above this settings, you'll get a warning. And that's how it should be...

You can choose in your gaslist different changing depths for each gas and you'll see the ppO2 for each gas. Then it's up to you to stick on the planned depth according to your bottom and/or travelgas and not exeeding pp02 1.4bar. Same with your deco gases...

I guess what you want would require to tell the OSTC which gas is used for travel, which for bottom and which for deco. Then you could set a range for each gas... But makes that's sense? IMHO it would make it much more complicated...

[sdol]

If you want to 2n warning u for at the bottom mix more than 1,4 u have to put CF46 to 1.41. If you change on deco gas nx50 at 21m (ppo2 1.55) the gas is RED. It's nothing wrong, but ever thime i change gas i have to look again at the compuer to understand what is wrong.

If u put cf46 on 1.6, you will loose the best mix (mod) calculations in the gas list, the warning of red at the bottom will not shoe red if u dive deeper as calculated, but istead you will get a claer number at the deco switch.

I hope now i made my point of view clear.
Please don't answer me like you have to calculate, stick to the plan and stuf. I'm doing that...it's just i think a small change in the gaslist will make a big difference.

Regards.

[scubatinoo]

I see now... CF17, CF18 and CF46 - and all about ppO2. That's confusing indeed. I hope that Matthias or someone else can clarify when and why CF17/CF18 and CF46 play together or not...

But IMHO it's not bad when gases with higher ppO2 then CF46 are highlighted. It brings you in mind not to use this gas in the wrong depth or at least it makes you think about if this is the right gas...

[wrobell]

actually i think sdol raises valid point.

the ppo2 warning is linked to MOD calculation. imho, those two should be separate.

it would be great if ostc calculated mod for two values of ppo2. that would be 1.4 and 1.6 by default. then it shall be configurable - i believe military guys (and some diving orgs) have different standards.

w

[scubatinoo]

I just played arround with OSTC-Planner. According to the software CF18 is the one who changes the MOD, and not CF46...

[sdol]

Yes, true cf18 sets MOD calculation.
If you put 1.4 in the gas list you'll have MOD for bottom mix, if 1.6 for deco gas . But you cant't set one for each gas.
With the CF46 (color) is the same thing. If you put 1.4 the red color will warn you for bottom mix and on the deco switch you will have nx50 in red till 18m.

[xymanuel]

Hi there,
i got the same problem here as sdol.

I opend a fearture request (#73)
https://bitbucket.org/heinrichsweikamp/ ... tatus=open

Kind reagrds
Manuel

[tramjoe]

I second the request, the ability to have different max pPO2 for different gases (deco/back) is nice to have. Typically, I allow for a higher pPO2 for deco...

[sdol]

Hi.
Is anything new with this. I upgraded to the 2.5 but still i'm not able to have different ppO2. Has anyone done this with success?
Regards.

[Bardass]

change your use !
you set PPO2 at 1.6
and for your bottom MIX, you set the MOD according to a PPO2 at 1.4