Worthwhile investment?
I was looking at this one...
AmoxTec Analox O2EII Nitrox Analyzer
What are some other ways to calibrate? The only one I know of is analyzing regular air at 21%. What if it's just you and a buddy only diving Nitrox and there is no regular air available to calibrate using that method?
$130 to replace the sensor after 4 years... That's nearly half the price of the entire device =-O What are some signs of the sensor going bad, just cross-checking with other devices?
We own one. It's been bulletproof.
As long as you're at sea level and not outside the temp/humidity norms, pulling the green inlet dome and waving it around works fine.
If the temp/humidity are enough to indicate a need for correction from the chart, you either:
A)skew your readings from the chart
B)calibrate from a cylinder absolutely known to have air.
...the latter is the easiest.
If you're at altitude, like diving at Lake Tahoe, calibrating to ambient air (removing the green dome) will also generate errors because of the reduced ppO2. Again, the easiest thing is to calibrate from a known cylinder of air.
Checking for lifespan:
Every 6 months I calibrate to a known cylinder of air. Then, I'll check:
- A cylinder of known 50% O2
- A supply cylinder of Oxygen (100%)
- A supply cylinder of Helium (0%)
If the meter quickly reads correctly (within 20 seconds or so), and makes it to within a % or two of correct readings, I'll sticker the meter and continue using it.
If it has an error of 5% or more I replace the sensor, but, I'm using it for checking technical mixes and need the span of 0% to 100%.
If I was strictly using it for recreational nitrox, which has a narrower span requirement, I'd replace the sensor when it had an errror of 10% at the extremes (Helium and pure Oxygen).
Hope this helps.
All the best, James