Owning your own Oxygen Analyzer

[BigJimDiver]

I recently (last year) became Nitrox Certified, and my 15 y.o. son will take the Nitrox course prior to an upcoming trip to the Cayman's on the Aggressor. When I took my course last year on the Aquacat they supplied Gas analyzers for my (and everyone's) use; a little more than half of the divers our week were diving Nitrox and all were using Aquacat's analyzers, so I deduced that nobody brought their own. My questions:

Is it typical for liveaboards and other dive operators to supply gas analyzers for their customers' use?

Since I currently only take ~1 trip a year , is it reasonable to rely on a liveaboard's gas analyzer to check cylinders before use, or should I take the plunge and purchase my own? I am trying to weigh which would be more reliable, a liveaboard's that is used constantly and is (hopefully) well maintained, vs. the reliability of an analyzer I purchase but use sporadically.

Is calibration critical, or is it simply replacing sensors after a certain amount of use or past a certain amount of time?

 

[BabyDuck]

it *is* typical for there to be at least 1 analyzer on a liveaboard or in a shop for customers to use.

you can make or buy your own for about $150 or a bit more.

calibration is critical before every use. the sensors fail with exposure, so it's an 'hours used' thing in general. you can buy new sensors separately when the old ones fail.

 

[DevonDiver]

If a nitrox vendor didn't have an analyzer available for customer use, then I'd be very dubious about using that vendor.

It's pretty much an industry standard that divers have to analyze and record their nitrox tanks before diving/upon reciept.

Any responsible nitrox dealer will have a log chart to be completed and signed by the customer upon receipt of their tank. In order to complete the log, the O2% must be verified. This is for liability reasons and also to conform with the way scuba agencies teach their nitrox courses. For the liability reasons, it makes a great deal of sense for the vendor to offer their own, calibrated, analyzer for customers.

The sensor in an O2 analyzer degrades with contact to O2. That means it's lifespan is dictated by use and storage. Most sensors won't last more than 18-24 months, even if rarely used.
If you are only diving a few times a year, it'd be hard to justify the cost/benefit of owning a personal analyzer.

 

[cool_hardware52]

I recently (last year) became Nitrox Certified, and my 15 y.o. son will take the Nitrox course prior to an upcoming trip to the Cayman's on the Aggressor. When I took my course last year on the Aquacat they supplied Gas analyzers for my (and everyone's) use; a little more than half of the divers our week were diving Nitrox and all were using Aquacat's analyzers, so I deduced that nobody brought their own. My questions:

Is it typical for liveaboards and other dive operators to supply gas analyzers for their customers' use?

Since I currently only take ~1 trip a year , is it reasonable to rely on a liveaboard's gas analyzer to check cylinders before use, or should I take the plunge and purchase my own? I am trying to weigh which would be more reliable, a liveaboard's that is used constantly and is (hopefully) well maintained, vs. the reliability of an analyzer I purchase but use sporadically.

Is calibration critical, or is it simply replacing sensors after a certain amount of use or past a certain amount of time?

If I went on one trip a year I would not own my own analyzer. The boat's should be ok.

Remember Nitrox class? The O2 analyzer should be calibrated shortly before each use.

For recreational nitrox mixes single point calibration against a known gas (air @ 20.9%) shortly before use should allow you to determine the O2 percentage in your cylinder with sufficient accuracy.

O2 sensors typically last 12-18 months so if you buy your own analyzer for once yearly use you will get about 1 trip (maybe two) for each ~$70 sensor.

Tobin

 

[Karibelle]

you can make or buy your own for about $150 or a bit more.

Make your own O2 analyzer? Have you done this, and do you use it?

 

[BigJimDiver]

Thanks all for the speedy responses. Yes, I do remember class, am religious (at least for the 1 trip I did on Nitrox up to now) about testing and logging O2%. I realize that calibration is necessary but didn’t recall if this should before each use, weekly, annually, etc., and from reading into this a bit understood the limited lifespan of sensors. My concern was that with upfront cost, sensor replacement, and calibration issues it did not seem logical to own my own unit, but I wasn't sure if it would be "irresponsible" for a Nitrox Certified diver not to have his own, or if I should be concerned about the accuracy of heavily used analyzers on a liveaboard; I thought it would be helpful to hear from more experienced Nitrox divers on their (your) general experience with the reliability/accuracy of operator supplied analyzers.

Thanks again!!!

 

[Wookie]

Yup, what they all said. I keep 2 or 3 analyzers on the boat so you don't have to.

 

[Bubbletrubble]

Make your own O2 analyzer? Have you done this, and do you use it?

@Karibelle: If you're looking for an easy DIY project, Oxycheq sells the necessary parts along with an instruction manual for about $100. It's called the El Cheapo II Analyzer Kit. That's a wonderful value considering that the sensor alone costs about $70.

 

[Karibelle]

Interesting. I have an analyzer, and I'm not sure I would trust one that I built myself. Might be fun to do and then compare how the DIY one works next to the other.

kari

 

[Jim Lapenta]

It works very well. I have one and it was also fun to build. If you go that way there are some things to be careful of but if you can use a soldering iron, razor knife, and a dremel tool it takes an afternoon working at a leisurely pace. And yes it is every bit as accurate as any commercial one I've used.