Quick Nitrox Question

[E8ArmyDiver]

Hi folks.As I no longer have a dedicated gas blender at my disposal, if I decide to get my EANx Cert.is an Analyzer a must have or do you Nitrox divers trust your fill station?Thanks very much...

 

[k ellis]

Hi folks.As I no longer have a dedicated gas blender at my disposal, if I decide to get my EANx Cert.is an Analyzer a must have or do you Nitrox divers trust your fill station?Thanks very much...

Well I use the one at my fill station since my shop I work out of is very dependable. If I travel though and am not familiar with the shop I try to get a second opinion.

 

[gcarter]

Ny LDS / fill station has an analyzer at hand for testing the tank when it comes off the whip. I calibrate and analyze the tank using their gear. You do not NEED your own, although it may give you some comfort.

I do test every tank, though, even though I generally only use straight 32 off of a membrane / bank system and I can see it on the compressor readouts.

My lungs after all

 

[Searcaigh]

My LDS blends also, and you are not allowed to take your tanks until after analyzing them and signing a chit, however I also have my own analyser, that I occasionally take with me if I am going to be using Nitrox blended elsewhere.

Membrane systems should be producing a fairly reliable standard mix, but I use the local analyser in these cases.

 

[antattack]

I was taught that I am responsible for testing logging and labeling every Nitrox fill I use. I can use the shops analyzer but I own my own. In shops where they do partial pressure blending, my fills have been off by more than 2% with enough frequency that I ALWAYS check. In my experience, the fill is O2 rich.

When I want to dive EAN 28 at the sport limit, i get a little emotional if my gas turns out to be 30.5 because the bottle was hot and the blender didn't get around to topping up the fill.

 

[Griffo]

I test the bottle at the shop (their tester), and just as I screw on the first stage(mine). Smarter divers than me have ended up dead due to tank mix ups. The cost of the analyser is trivial compared to funeral costs.

This way I also am using two different analysers. If there is a significant difference I would thumb the dive.

Replied using Tapatalk. Please forgive my typing.

 

[fugly]

Pretty much the same here. I used the LDS analyzer. I first used a regular tank filled with air to calibrate the analyzer before I check the nitrox fill. I always leave my tanks overnight to let them cool down and homogenize before I analyze my tanks. My LDS policy is +\- 1%. Which I think is stated in the padi ean manual. If it is beyond this range, I have a choice to have it re-filled or accept the incorrect filled tank free of charge. Bottom line, you are responsible for checking your own tank. You should verify the EAN mix and verify the MOD. never trust the label on the tank as mistakes can occur.

 

[E8ArmyDiver]

Thanks guys,kinda figured it would be prudent to factor the cost of an analyzer into the Cert.By the way antattack,I was stationed at Ft.Ord from '79-'83 with the 7th.Infantry.When the firing ranges along Stillwell Beach were hot we would patrol Monterey Bay in a 65' Q-Boat keeping civilian watercraft out of harms way.On the weekends we would take the boat up to SC on a "Training Mission",anchor just of the beach,party all night at the Boardwalk & dive the coastline all weekend.Man I LOVED Santa Cruz.

 

[Colliam7]

if I decide to get my EANx Cert.is an Analyzer a must have or do you Nitrox divers trust your fill station?

Tough question to answer, as worded. Having your own analyzer is never a bad idea. So, if you buy one as part of the overall process of getting certified and using EANx, good for you. But, having one is not essential, either. First, you will always want to / be encouraged to / be required to analyze your gas at the fill station, before walking off with the tank, certainly before diving with it. So, you really don't have to 'trust your fill station', nor should you. Second, I have never been in a situation where an analyzer was not available for me to use, at the point of fill. I guess there might be some fill station, somewhere, for which that is not the case, but I have not experienced it. Any competent station wants to limit their liability, if nothing else, by having the customer sign off on the mixture they pick up, so they have analyzers available for use. Third, fill stations will miss the mark on partial pressure blends at times, but that generally has little to do with incompetence or laziness. And, the miss is going to be on the rich side most of the time - it is much easier to add air to an almost full cylinder than it is to add oxygen. When I blend, I prefer to fill the tank to service pressure, let it cool and let the mixture become homogenous, then top it off 12-24 hours later. But, periodically the customer will show up a bit early, or I will get busy and not get back to the 'top off' before the due date / time, and the mix turns out to be a bit 'hot'. However, it is never a problem to make the final adjustment right there - it takes less than 2 minutes.

Personally, when using EANx on recreational dives, I will plan the mix conservatively - e.g. I will plan for a mix that gives me a ppO2 of 1.2 at my maximum depth. I still get the benefits of extended bottom time. If I pick up a bottle when traveling and the mix is richer than I wanted, I usually don't worry about it - I simply adjust my maximum depth. Since I have already added a degree of conservatism in the planning, it is seldom a problem.

 

[ajduplessis]

Any "trust me" situation in diving is asking for trouble and this is also true for Nitrox fills. All Nitrox shop MUST have an analyser and all fills must be checked and signed for by the diver. It is you responsibility and right to check you mix.

I would not spend the cash on an analyser, its really not needed. But you have to analyse your fills yourself!!!