dive tables

[Charlie99]

cornfed once bubbled...
Chris,

The link uses Navy Tables, PADI uses (I think) Navy Tables that have been doppler corrected/modifed and you're Mosquito uses RGBM.

1 out of 3.

Yes, the link has Navy (pre-doppler) NDLs.

PADI has their own table, developed ScubaBoard's own Dr. Deco at the related company, DSAT. Before the PADI/DSAT RDP release (1987??), PADI used the unmodified pre-doppler Navy table,

The Mosquito uses dissolved gas tracking (Haldanian model), not RGBM, but modifies the M values to emulate RGBM.

 

[dad6b]

Charlie99 once bubbled...
1 out of 3.

Yes, the link has Navy (pre-doppler) NDLs.

PADI has their own table, developed ScubaBoard's own Dr. Deco at the related company, DSAT. Before the PADI/DSAT RDP release (1987??), PADI used the unmodified pre-doppler Navy table,

The Mosquito uses dissolved gas tracking (Haldanian model), not RGBM, but modifies the M values to emulate RGBM.

So is "Suunto RGBM" not a real RGBM? http://www.suunto.com/v2/datafiles/specs/suunto_techfeat.pdf

Drew

 

[cornfed]

Manfred once bubbled...
Any Nirtox tank should be marked - period -

I never said it wasn't... mark it with the old MOD and as 21% O2.

If there's only 800 psi left just drain it and get air, that way you know what you're diving with.

What I'm suggesting is no different then how you handle a fractional percentage. It is just more extreme.

Cornfed

 

[Charlie99]

dad6b once bubbled...
So is "Suunto RGBM" not a real RGBM?

The VPM program and other real RGBM programs will track variables such as estimated bubble radius, as well as estimating tissue ppN2 by tracking N2 loading in dissolved gas model compartments. Only recently have any computers been put into production that actually implement a true RGBM model. They weren't by Suunto.

On the other hand, you can do a pretty good job of emulating the RGBM results by just tracking dissolved gas loading, and adjusting the M values/NDL limits in response to things like yo-yo profiles and rapid ascents. To the best of my knowledge, that is the method used in "Suunto RGBM". It appears to work quite well.

 

[radagalf]

You should let your dive shop know what the contents are when you bring the tank in, hence the contents label should be left on. Why??? Well here we go:

1) Due to the enriched air content of the tank, if it is being hooked up to a fill whip, and once you crack it open the tank and the pressure in the whips equalizes. There is the possibility for your enriched air to move up into the fill system. If this system is not oxygen cleaned, than it may lead to rupture, fire, or worse. Although this is a slight possibility, it STILL EXISTS. By not notifying the dive shop of your tank(s)' contents, you will be legally responsible for any damage that is incurred.
(Although this isn't related to nitrox fills, it is an interesting account of a tank explosion and the damage that can be done: http://www.connected.bc.ca/~baquatics/explode.html)

2) All fills that have more than 21% oxygen have to be logged by the shop as enriched air fills and the proper paperwork done. This includes fills which are just air top-ups of a previous enriched air.

Frequently I get a 40% oxygen mix and do some dives with that, I than get it topped up, find out the % O2, calculate my MOD, and get another enriched air dive out of it. I do this until I get under 22% and thus am able to usually get 3 or 4 enriched air dives out of one fill. Each time I make sure to calculate my MOD, my EAD, and my % maximum O2 exposure. I could use my 40% MOD and dive using air tables, but I feel that I am practicing my skills more by planning it out and knowing exactly what is happening with my air, equipment, and how I can adjust my dive profile if an emergency situation arises.

 

[Genesis]

that has a fill protocol that allows gas in the tank back up the whip isn't one that you want to do business with in the first place. Its a bad practice and should not be done.

That solves that problem.

 

[blacknet]

Hello,

Order the IANTD EAD-MOD nitrox tables, C-3200 imperial and C-3204 metric. They will tell you everything you need to know.

Ed

 

[cornfed]

Genesis once bubbled...
that has a fill protocol that allows gas in the tank back up the whip isn't one that you want to do business with in the first place. Its a bad practice and should not be done.

That solves that problem.

Beat me to it...

 

[Diver0001]

KWS once bubbled...
after using a nitrox mix and recharging to full preasure with air, the mix is no longer a standard 21,32,36%. perhaps 27 is the resulting mix. where do i get tables for that mix and subsequent reducing mixes untill the tank finally gets back to 21%. is there a reference that will give me tables for 25% or 29% other than the naui white wheel that converts depth at % to the 21% tables???
possibly a software package or a site to download the tables from. it sems silly to use the more conservative of the computer vs. % table in planning, knowing the table always wins. then to be cut off from the appropriate tables and made to rely on the computer that up till now has not been the conservative choice.

example. 36% nitrox dive return at 800lb. recharg to 2610 with air the resultant mix should be somewhere around 26% where is the table for 26% mix?? 29%??

is this something to adress to naui or padi ect ?????


regards

didn't they cover this in your nitrox course?

R..

 

[MikeFerrara]

cornfed once bubbled...


They don't need to know what your tank previously contained. If you had a nitrox tank that you used all but a 1/4 of and ask to have it filled with AIR the only thing you need to tell them is, "here's my tank... fill it with air." Oh sorry, they might also need to know what fill pressure you want.

How is telling them the gas you last dove going the help in this situation?

Cornfed

Ps Too much information is just as bad as too little.

Well, If I'm filling a tank I want to know what's in it to start with. If there's a reason you don't want me to know then don't bring me the tank. For one thing we keep a fill log that shows we both knew what was in it. We don't do it for air, though it probably wouldn't be a bad idea, but it's required for nitrox and trimix. If you had nitrox in it to start it'll be nitrox when we finish, and we'll enter it in the log.