Trimix Blending Risks with a Small Operator?

[drainaps]

Good evening,

I’m considering a Trimix course with the operators I’ve done my Extended Range course with. I’m however slightly uncomfortable with the fact that very few times they dive Trimix. They’re very competent people, and do a lot of Nitrox and CCR Tec diving, but still.

(1) What should be the basics I should consider, as a total rookie, in order to make an assessment of how safe am I going the Trimix way with them? I’m reasonably familiar with gas chemistry, so please don’t be afraid to shoot your technical stuff at me.

(2) Would it be an overkill to buy my own helium / oxygen analyzer to be sure that I can check on things with properly calibrated equipment, or would I need some specific training for that?

Thanks a million for help.

 

[JohnnyC]

If they can blend nitrox and they dive closed circuit, they can blend trimix. That being said, it's always a good idea to have your own analyzer. I prefer the Divesoft.

 

[swimlikethefish]

Mixing the oxygen in to the tank is the most dangerous part. Once that is done you are essentially dealing with a high pressure cylinder the rest of the steps. You said they mix ccr cylinders... One of those is oxygen, the other being diluent (usually trimix for deeper dives)

If they own a booster chances are they are more competent than you are giving them credit for. There are plenty of books to read on this subject that will give you a ton of information. For a quick assessment, ask how many bottles of helium they go through a year. That will give you a rough idea of how much mixing they do.

 

[fullytek]

Having you own nitrox analyzer is an absolute necessity if you are a nitrox diver

Having your own trymix analyzer is an absolute necessity if you are planning on doing any trimix diving.

This should be a standard adapted by all technical diving agencies.

Don't be cheap dont trust some one else's analysis.

Shame one any diver who owns a shearwater or comparable computer but not an analyzer

 

[helodriver87]

+1 for having your own analyzer. The divesoft is probably the best one out there. Nobody gets into trimix diving to save money and, while it's not the sexiest way to spend $700-800, it's probably one of the most important pieces of gear I own.

 

[Jeremy Williams]

... it's not the sexiest way to spend $700-800

The Divesoft Solo is just $650 and available from all the usual suspects. I think that It is a pretty solid value for that price.

 

[DeepSeaExplorer]

You don’t really need a Trimix analyzer. Test the O2 with a Nitrox analyzer, since O2 content is the most important factor.

Then, test the Helium by breathing it. 21/35 will give you the Donald Duck voice after 2 of 3 breaths. Higher mixes like 10/70 will give you the DD voice after one breath. Unscientific I know, but a good double check.

 

[helodriver87]

You don’t really need a Trimix analyzer. Test the O2 with a Nitrox analyzer, since O2 content is the most important factor.

Then, test the Helium by breathing it. 21/35 will give you the Donald Duck voice after 2 of 3 breaths. Higher mixes like 10/70 will give you the DD voice after one breath. Unscientific I know, but a good double check.

It'll do in a pinch. And I occasionally cross-check the fancy analyzer with a quick stick just to make sure neither is drifting. I do find that it's really valuable to be able to analyze helium content since I'm mixing my own a lot. Helps me fine tune the process. I'm also just anal about gas analysis. The helium isn't the most important part, but I still want to be able to verify exactly what I'm breathing. For peace of mind more than anything.