Nitrox PPB

[Packhorse]

I have just made up a XL spreadsheet to calculate gas requirements for mixing nitrox and Trimix into tanks. Unfortunatly I have no idea if it is correct or not as I have nothing to test it against.
Anyone know the formula or have software to check it against?

my speadsheet can be found at http://www.caralarms.co.nz/dive.htmdown the bottom of the page.
Thanks

 

[SparticleBrane]

I am not sure if they are correct or not. However, I have made some spreadsheets in the past for using 40% and 38% premix. They're on my other computer which I don't currently have access too. Whenever I get back to my iMac I'll perhaps post them online.

edit: I made them for the shop where I used to work, and they have a slightly different mentality than what yours appears to be. If I'm reading it correctly, on yours you input how much you need and it calculates it automatically? On mine, they were set up this way:
If you have 40% premix, to fill a tank to 32%, you need to fill it to xyz PSI of 40% premix then top off with air. It had all values from 26-40% ranging from 100-4000psi.

 

[AndyNZ]

packhorse - i can get you a copy of the DSAT blending tables if you like so you can check against those?

 

[Packhorse]

Also how do you calcutate EAD when using Trimix? Do you use the same formula as when using Nitrox?

 

[Packhorse]

packhorse - i can get you a copy of the DSAT blending tables if you like so you can check against those?

Thanks that would be great. I will PM you my email.

 

[SparticleBrane]

Unless you're using heliotrox, then it doesn't have an EAD. Instead, it uses END...
Perhaps this will help?
http://www.breakthrudiving.com/pdfs/standard.pdf

 

[Packhorse]

If I'm reading it correctly, on yours you input how much you need and it calculates it automatically?

Yes that correct. Input the mix thats in the tank to start with and the mix you want to end with and hopefully it will calcutate the gases required in Bar.
I was going to do it for diffent mixes being added to diffrent mixes at diffrent starting pressures but as you could imagine there would be so many diffrent mixes that it would be pages and pages long.

 

[SparticleBrane]

Well that depends--if you wanted to go that route I would suggest using air or 32% as the only possible mixes for making trimix. That way you don't have to worry about other stuff thrown in.

edit: The specific reason I did my spreadsheets that way was due to their usage. They were printed out and taped next to the filling station so that they were there whenever someone needed nitrox.

 

[PerroneFord]

I have just made up a XL spreadsheet to calculate gas requirements for mixing nitrox and Trimix into tanks. Unfortunatly I have no idea if it is correct or not as I have nothing to test it against.
Anyone know the formula or have software to check it against?

PM me about 4 or 5 examples, and I'll run it against my blending program.

-P

 

[Packhorse]

I only really made this so I can learn a bit more about PPB. That and I got a bit bored over the weekend because I couldnt go diving.
I havent even finished my Nitrox class yet let alond Trimix.
I have to admit I had to look up Heliotrox.
So let me get this correct.
Trimix is any mix of O2, H and N (or more specificly ang 3 gases)
Heliotrox is a specific mix of 02, H & N 26/17/57
Heliox is a mix of O2 & H
Nitrox is a mix of O2 & N