View Full Version : O2 Analyzers, Are They Worth Having?

08-10-2007, 10:26
Who here has an O2 analyzer? Every time I get EAN mixes from the LDS they have a shop analyzer on hand to test the tank. So I have never needed one. However, it may be a good idea to carry one as a confirmation of the %O2.


08-10-2007, 10:40
I don't have one yet...but I will get one. I think if you dive Nitrox frequently, or have multiple tanks it's a good idea to have to avoid any confusion as to what mix you're using. My fiance and I both dive nitrox and have multiple tanks between us. Often times they are filled with different mixes. It's just another safety to make sure you have your numbers correct before diving. Not to mention that I've heard a mix can change slightly over time. I've never experienced this, since my tanks don't usually stay sitting full for that long.


08-10-2007, 11:28
Unless something bad happens mixes don't change over time once they're mixed up. Measure today and it will be the same 3 months from now.

As to needing one, yes I believe if you dive it you need it. I've been to shops where theirs quit and I had to use mine or not get a mix. I've seen mixes that didn't come out right. For some reason when I got the tank back the mix ended up way too strong for the dive I was going to do, even though they analyzed it.

I believe it's a good idea to second check a mix.

08-10-2007, 11:47
Yes, get one. Like Matthew said, sometimes the shop's analyzer isn't working. Another issue is you never know how well maintained the shop's analyzer is. If you go on any dive vacations where you dive nitrox all week long, you also don't have to wait for the boat analyzer, if they even have one. I also like to analyze right before the dive. It's not that I think the mix is going to change. It's just my confirmation of the mix I have in the cylinders.

08-10-2007, 12:36
I don't believe a mix would change over a practical length of time you would let a tank sit idle unless you hade some serious corrosion going on, in which case the oxidation would reduce the o2 level. At that point you've got much more series issues at hand.

I've never felt I needed my own analyzer when filling at a shop, but I admit to concerns with regard to the accuracy of a few units I've used aboard charter boats when renting tanks through that service. The o2 sensors wear out pretty quickly and they need to be well cared for. Without any imperical data to back me up, I just 'feel' the reading seem to vary more when you're aboard.


08-10-2007, 15:12
If you dive Nitrox all the time they are probably worth having. I only use it occasionaly, and I use the LDS's analyzer.

08-10-2007, 15:41
My buddy has 1, and since about 80% of my dives are with him, I haven't really needed 1. I may get 1 of those Oxycheq el Cheapo analysers. I think it would be fun to build.

08-12-2007, 11:08
Yes ... Makes life easier when you need one. A group of 12 walks in before you and are waiting to analyze their gas. Just use your own. Your cylinders arrive at the dock but no analyzer. Jusr use your own. Etc.

09-17-2007, 23:21
Also a good thing to check the shops analyzer. The shops might say 26% but if the sensor is old then it could be off a couple %. Now that probably isn't going to kill you but it sure could make a bit of difference with your MOD.

09-17-2007, 23:49
I purchased one earlier this year...which I will take to Wakatobi....this last year in Rangiora we were diving mostly 36 nitrox.....with an analyzer that worked half the time.....not worth taking the chance....safer diving!

09-18-2007, 10:12
I say yes cause it's your life. I've seen gauges at shops get dropped, beat up, etc. Never hurts to double check. I have an analox I bought 3 years ago. I like it a lot.

09-18-2007, 10:13
BTW, one shop I went to had a digit on the gauge that didn't work right. You could mistake a 3 for an 8. And they kept using it!

09-18-2007, 10:15
if you dive occasionally and get your fills only from your LDS that have an analyzer then you can use it, but as you start diving more and more with Nitrox and travelling to places (vacations) where you want to use Nitrox, then having yourown is a good idea.

09-18-2007, 10:23
I think if your diving with Nitrox on a regular basis its worth while in getting your own O2 Analyzer. I have one.

I have been on a Liveaboard and they had their two Analyzers crap themselves on the trip. Lucky someone had brought their own.


09-18-2007, 16:24
I have a very trustworthy shop, and I know they are religious about keeping their analyzers accurate, so I feel 100% using their shop analyzers. Likewise, I trust most of the boat's analyzers that I've been on, but there are one or two that give me pause. Then there are the times I've been diving in a remote place and wanted to confirm something, and wished I'd had one.

Finally there are the times I bring Nitrox tanks onto a boat that doesn't have Nitrox on board. When you're diving doubles, that leaves quite a bit of gas in the tanks, so once they top off with air, having my own analyzer means I can analyze the resulting mix (often ~28%), and gain the extra BT (MOD usually isn't a concern, concerning the MOD of 28% and the improbability of doing a second dive of the day that would exceed that depth!) and offgassing advantages that 28% gives me over assuming it's all air.

So yes, I have been very happy to have my own analyzer. I dove for a long time without one, however, and did just fine, but again, I trust the gear at the shops and boats I dive from (with Nitrox) most frequently.