Always Analyze!!!

[jblack]

Picked up a 3L o2 bottle from a vip the company let me know they they pumped 500lbs of nitrox in the bottle. Brought the bottle to a Tec shop down the street and advised them the bottle was just vip and there is 500 lb of nitrox in it. keep in mind this bottle is marked 100% 02 ......... i advised the shop of the nitrox in the bottle and even told them to empty it. They took it in the back and soon returned with the bottle advising me it was full with 02....... Analyzed it this morning to find it at 80% they never emptied the nitrox or analyzed it! and yes i checked my analyzer with a known 02 bottle to be sure........
This shop is very familiar with ccr's and know 100% o2 is a must.
Be safe, and ANALYZE!!!!

[FW]

You should have dumped the nitrox before you went into the shop.

[jblack]

Agree..... figure when I told the fill man that he would have....but I caught it.

[oya]

I realized that I had forgotten my analyzer at home when I was about to put the reg on my 50% bottle.

"It's OK," I decided, "I mixed this bottle myself. Of course it's just right."

But some little voice in the back of my head started nagging right away.

"Hey Dave," I asked the mate, "Let me borrow your analyzer for a second."

See, that wasn't so hard... aaaaaaaaaaaaaaaaaaaaaaaand... it was 80%

I was very glad I didn't switch to that at 70 feet. I am also glad that I have that little voice in the back of my head to remind me when I'm being a dunce.

[Nitrogenius]

The real big question to follow up and analyze though is, how does a bottle that one filled himself as 50% end up being 80%


Also it is a good example that actually SOP of gas mixing has been broken as a tank needs to be analysed after the fill and marked with the results.


This is how I handle it at my place adding analysis result and date to such bottle. Doing so though I mostly do not analyse at dive site unless analysis had been a long time ago or a tank was not properly marked after analysis (tape ripped off, etc.)..

[oya]

The real big question to follow up and analyze though is, how does a bottle that one filled himself as 50% end up being 80%

This was before the time of blending apps and I was partial pressure blending with a calculator. I'm guessing I absentmindedly did the math for 80%.

But I really don't remember what was going through my head when I had blended or what was going on in the shop. The only part of this that was really seared into my memory was relief and embarrassment when the analyzer started to stabilize.

[LMN]

Did you confirm with a different analyzer that it was only 80%? First inkling I had my sensor was bad was when it read 80% on my O2 bottle. Sure thing, it was 100% when checked with a good one.

[tbone1004]

Did you confirm with a different analyzer that it was only 80%? First inkling I had my sensor was bad was when it read 80% on my O2 bottle. Sure thing, it was 100% when checked with a good one.

why you should dual point calibrate and verify linearity

[Aquabot]

why you should dual point calibrate and verify linearity

Also check the battery. Low voltage gives some "off" readings as well.

Sent from my XT1650 using Tapatalk

[MORGAN]

A principle of critical care nursing that crosses very nicely to cave diving: If it crosses your mind even for a moment to double check something, double check it. Don't talk yourself out of confirming something important because you're tired, or in a hurry, or have to pee, or you don't want to hold other people up...the little voice in the back of your head that Roger mentions is there for a reason.