Tri-Mix Analyzer

[Superlyte27]

What's the best Tri-Mix analyzer?
Hoping for ease of use and longevity.

[RN]

I don't know that there's really much difference between them. I have one I've had for about 4-5 years now and it still works fine. Only thing I've had to replace is the O2 sensor a couple of times.

[DA Aquamaster]

There are some differences in how the helium is analyzed (chemical sensor versus not) but given the longevity of a chemical based helium sensor (10 years or so), I don't see the need to complicate matters with more cpomplex electronics.

There are also diffences in the speed of the analysis as well as in the calibration steps. Some are faster than others and some require correction based on temperture and humidity.

My preference is the trimix analyzer made my Analytic Industries. It comes in it's own watertight protective case, gives very fast readings, self compensates for temperature and humidity, runs for months betwene charges on a standard rechargeable battery and could be plugged in if used continuously in a shop, etc.

The Analox also makes a trimix analyser. The most recent iteration is smaller than the last one, but is built on/in a water tight case rather than being contained in one, so you benefit in terms of smaller size, but you lose a bit in terms of protection for the sensors, buttons, screen, etc.

[SlowDiver]

Check out the Divesoft HE/02 analyzer, it is the one I use. It was not the fact that it uses no HE sensor but the way the 02 is calabrated, since a accurate 02 reading is more important than the HE reading.

Safe Diving
Fred

[Walter Pickel]

Check out the Divesoft HE/02 analyzer, it is the one I use. It was not the fact that it uses no HE sensor but the way the 02 is calabrated, since a accurate 02 reading is more important than the HE reading.

+1 on the analyzer. Don't agree on the greater importance of either gas. Incorrect He measurements lead to incorrect N measurements that lead to incorrect deco assumptions.

DiveSoft HE/O2 Analyzer - http://www.golemgear.com/p-544-dives...yzer-bare.aspx

[Michael Stroeck]

+1 on the analyzer. Don't agree on the greater importance of either gas. Incorrect He measurements lead to incorrect N measurements that lead to incorrect deco assumptions.

DiveSoft HE/O2 Analyzer - http://www.golemgear.com/p-544-dives...yzer-bare.aspx

+2. You can also use it as a volt meter for testing your various batteries: http://www.addheliumstore.com/divopl.html

[FW]

+2. You can also use it as a volt meter for testing your various batteries: http://www.addheliumstore.com/divopl.html

Cute, but you can buy a voltmeter for less tha $38

[Michael Stroeck]

Cute, but you can buy a voltmeter for less tha $38

Sure - but that's an extra piece of gear. Having it all in one box is convenient for us travelling divers (Most stores here in Europe sell the analyzer in a custom case with flow restrictor and the Ohm and Volt meter plugins.)

[diveongas]

What's the best Tri-Mix analyzer?
Hoping for ease of use and longevity.

The best was probably the first, the ATOMOX. It was a very, very expensive unit that was built like a tank, and almost weighed as much!

The helium "Sensor" used wire heating elements to measure heat loss to determine gas composition. The element was borrowed directly from industry and has a sevice life of greater than TEN CONTINUOUS years. There is no degradation that occurs during downtime/storage. Realistically, it will last until you dropped it too many times or the onboard electronics get done in by voltage spikes, courtesy of your local power company.

Also for note, the sensor could deal with high oxygen concentrations with the helium and not catch fire or explode. This is normally not a concern since most trimix has O2's of less than 21%. But this unit would allow testing 50-50 heliox in case you have deep pockets and do things the U.S. Navy way and, of course, TriOx 30/30 or any other concoction that is now the darling of recreational diving.

Initially, they retailed for as much as $2K. I think that Atomox has gone kaput. I got one, I think from a creditor, for the princely sum of $399. They are still out on the used market and may still represent a good value versus current models out there.

Of course, you can stick to heliair and skip the He analyzer thing altogether.

[DA Aquamaster]

Way back in the day when I first started playing with nitrox and trimix blending, you could not get a practical and portable helium analyzer. The practice was to partial pressure blend and just ensure you got pressures and the math correct, then analyze the O2 content as a back up/accuracy check for the mix. Assuming you used a reasonably accurate pressure gauge and sound fill practices (slow fill rates, letting the gas cool between steps, etc) and got the math right, the mix would be right. And for some mixes, accuracy was not all that big a deal as long as the resulting proportions were right - for example mixing something in the vicinity of 21/35 where you'll have 1 part helimum and 2 parts 32%. Even if the gauge is 200 psi off, the mix will still be right as the proportions will be right - as long as the error is constant in the 1/3rd and 2/3rd service pressure ranges that matter.

In practice, I agree the O2 percentage is more critical as it directly impacts both the MOD and the deco obligation. In contrast, being +/-5% on the helimum won't have a noticeable impact on the deco required, or have much of an impact on the END.

Still, I really like being able to check my mixes now as it adds a great deal of confidence, but to be honest, I tend to blend faster then I did before and I suspect my mixes were just as accurate (if not more so) in the pre-trimix analyzer era as you could not safely take short cuts and precision was much more important since you had only limited means to verify the mix.