Quote: (Originally Posted by
Paul Brookes)
Hi
Therefore, I expected my lds to have the facilities to verify the contents of a fill they provide. However, when I got my diluent and stage cylinders filled recently, they advised me that they do not have an He analyser as most of the trimix divers have their own. So I had to take it on faith that the he content was correct.
If I was performing my own blending, then I would buy my own analyser, but surely if a shop is supplying the fill, they should be able to analyse it.
Is this right? Am I expecting too much here?
Thanks, Ramble over.
Paul
Actually there are no stats for how many mixes are off enough to cause serious problems.
I agree, any dive using a mix someone else blended is a trust me dive. You are relying on someone else to mix what you will be breathing. If you payed him for the service, he/she will have a duty to perform. A contract of sorts, and they will be responsible to take any reasonable and prudent steps to assure they are selling you what they say they are.
If I mix my own, I have no one to blame but myself.
Any operator, from a legal perspective, who is mixing and selling a trimix blend should have an analyzer available. The technology is more advanced than it was ten years ago, and it is fast becoming a standard of the community.
Though you, the user, is ultimately responsible for the mix, I would not want to have mixed something in todays environment without someway to quantify and verify what I sold you.
For years we analyzed the O2 and that was sufficient. The technology supported it. Now that He analyzers are fairly common, it would be hard to justify not having one. (If in the mixing/sale of mixes)
There is nothing really wrong in not analyzing the He, when in mixing it yourself, your O2 percentage works out in the final mix. Afterall, the O2 percentage is much more critical than a couple percentage points on the He.
Dale