Nitrox Blending

[markblythe@lineone.ne]

I have some questions about nitrox blending, I am working with a PSA nitrox blend worksheet, and have been told that it is easier to work with a HAVE, WANT, NEED table can anyone tell me how it works?

 

[JBRES1]

Welcome to the board.
First off you should buy the "Oxygen Hacker's Companion"
It is a very good book to own if you plan to do your own blending.
My take on Have, Want , Need.
You have a cylinder with lets say 32% at 1000 psi, and want a full cylinder ar 36%.
There is your have (32% at 1000), you want 36%, you will need to add 430 psi of o2 and the balance of 1570 of air.

Hope this helps,
Jim Breslin

 

[battles2a5]

The Oxyhacker's Companion has templates for the Have, Want, Need calculations for Nitrox and Trimix, with explanations on how the calcs work. It's a great book.

Airspeed Press Homepage - Books For Serious Divers

 

[Scuba Duck]

Here's a useful tool for Partial Pressure Calculations. It was initially designed to work on the Iphone, but works well using Firefox or Safari browsers. Internet Explorer doesn't display well.

Nitrox Blending Calculator

 

[pescador775]

Here is your reference; read it all the way through:

http://www.scubaboard.com/forums/co...tems/236471-how-do-i-get-28-1000psi-32-a.html

 

[CraigAClark]

I'm not sure what your reference "PSA" means, but to me it is Pressure Swing Adsorption, indicating a system designed to produce oxygen. Normally these units produce 93% +/- 3% and require an additional unit for higher purity. This must be taken into account in mixing calculations. Most aviators/medical grade O2 is 99% and I believe most calculation sheets use this % as a basis.

Craig

 

[pescador775]

PSA is a British instructional organization. The usual terms for their name, professional this and that. At a glance, they seem to emphasize the complexity of gas mixing while specifically mentioning "complex equations". Personally, I feel that deco schedules cooked up for mixed gas diving can be more complex than mixing/blending. It may just be that they have made their instructional materials unnecessarily complex.