Analysing gas and a bit of a rant..

[scribley]

Long story... Went to my LDS to pick up my filled bailout cylinders. One of them was 18/45 and I wanted to use their He analyser to check the mix as I don't have one.
Turns out there was a blockage in the restrictor or something, so I wandered round the shop browsing while they fixed it.

As I was paying for something, I can hear copious amounts of gas from my cylinder being leaked into the air as they are trying to get a reading on the analyser. So I promptly go over to the filling bank to see what's going on. Can't get it to work, so they take off the restrictor, crack the valve a little to try and get a reading. The He amount pops up as 47% and then disappears as the gas stops flowing. Oxygen is 18%.

Now I know He analysers can take a little time to settle, so I'm not sure whats in the mix - potentially between 45-50% I would guess. I'm not happy that I know what it is, but the dive shop response is, you know what the oxygen content is, so therefore the mix is right.

Is this correct?? Should the dive shop be happy with me taking away a cylinder unchecked? Should I accept that this is an 18/45mix because the o2 is right?

The shop owner's argument was back before He analysers, you just went with the o2% and if this is right then you had the correct mix. Now I would be happy with that if I could be guaranteed that the cylinders weren't filled by a numpty..
Wondered what you thoughts were.

and to top it off, they only have 3 and 7l cylinders on their system, so I was charged for 60% in a 7l cylinder for my ali40 (5.4l)
This is the same shop that adds 40bar to my o2 cylinders and charges for a full fill.
My cylinders I ordered from them hadn't even been ordered a week later, so ordered them myself from ap valves and they arrived in 2 days!

Now I really want to support my LDS but it's just not worth it for me. Fortunately, I'm moving so I don't have to use that dive shop ever again.

[nigelH]

Originally Posted by scribley

The shop owner's argument was back before He analysers, you just went with the o2% and if this is right then you had the correct mix. Now I would be happy with that if I could be guaranteed that the cylinders weren't filled by a numpty.

<shrug>
I've thrown a mix back because I ordered 20/30 and got 20/15 or so. Not something I want to take to 60 meters. I'm far enough out of my skull on 20/30.

These days I blend and measure my own as it seems to be the only way to do it and get it consistently right.

[IanDennis]

Wrasbury are normally spot on when they mix my gas - always what I asked for

Little bit further to travel but you can always drop them off on a Wednesday night

Ian

[scribley]

Originally Posted by nigelH

<shrug>
I've thrown a mix back because I ordered 20/30 and got 20/15 or so. Not something I want to take to 60 meters. I'm far enough out of my skull on 20/30.

These days I blend and measure my own as it seems to be the only way to do it and get it consistently right.

It seems to be the only way to go. Unfortunately, as I live in rented flats I don't have the luxury of a garage to store j's and boosters.

I'm now doubly irritated because the "new" cylinders ap valves have sent are 2.5 years old...