Trimix Fills and Helium Analysers

decoweenie

IMHO, everyone should know the O2% before making any dives at ANY depth.

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Nicholas von Rosen

I always do heliair dives, - so really no need for a helium analyser

Nick

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Paul Brookes

Thanks for the input.

I accept that analysing the O2 gives a good indication of whether the blending has gone to plan, but it still makes me nervous.

I don't think there's much choice in the way of Trimix blenders in my area, so I might have to bite the bullet and get my own analyser. Either that or watch them perform the fill.
I'm still new to deepish dives and want that mental comfort factor of knowing exactly what I'm breathing.

Cheers, Paul

Doppler

Amen... with bells on.

Mike

And that's the important point.

Back when I had a life and a working rebreather, mystery mix was just fine. Start with something close to either 10/50 or 20/50 - Anything around 50% He is fine. Then top off with air for the second days diving. 13/30 sounds great.

The point of He is to reduce narcosis.
The point of O2 is to keep you alive.

A CCR manages O2 for you.
Manage narcosis yourself. If you feel too narked, call the dive.

Let's be realistic here. Most of us have done 50+m air dives often enough. For the profiles we normally run, even a 10% variance in He isn't going to make that much difference to either narcosis or to run times. So for the majority of dives, anything with some O2 and a slug of He is just fine. If the CCR is working, and you can still think, life is good. Hey - do an extra 10 minutes at 6m if you're nervous, last time I did I had a great time with a seal that I would have missed otherwise.

Carry bailout, and use it if things go screwy.
Relax about the 3rd decimal.

Mike

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trob09

My little story:

A few years ago, before I saw the light and went CCR, I went to pick up some stage tanks for a 230'/70m dive. The shop had a trimix analyzer, so did I. When I hooked up the analyzer to verify the contents, I got the right O2 percentage (15%) but just about half of the He percentage (25%). I was ready to "trust the math" and use the tanks but needed to fill my suit inflation tanks with argon before heading off to the dive boat. So I go into the basement of the shop (argon was disconnected) and see one of the helium whips connected to an argon tank. The shop helper had mistaenly hooked up a n argon tank to the fill panel & I had a "quad-mix" with about 25% argon.

Since then, all tanks get analyzed with a n O2/He analyzer.

T

UWSojourner

If you don't know the gas you're breathing just think of it as an ad-hoc, and unknown, conservatism adjustment on your deco plan. You know, like VPM-B+1, VPM-B+2, except you choose the VPM-B+-X option.

As Reagan once said, "Trust, but verify."

Philippe GERIN

Check here, they running a sale: $400 for He and $550 fo Heliox
ATOMOX Inc. - Clearance Items
With the £ so high, it's simply a bargain.
Best
Philippe

Paul Brookes

That certainly is cheap.
I've not heard of them before (but then I am a trimix newbie). A quick google seems to say they are ok, but does anyone have any 1st hand experience?
Is this a good buy, or do you get what you pay for?

Thanks, Paul