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CO Analysers

Discussion in 'Advanced Scuba' started by Diver71_au, Jan 16, 2018.

  1. Angry Turtle

    Angry Turtle Contributor

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    So do you place the dome on the sensorcon unit and use it just like you did with the analox?
     
  2. grf88

    grf88 ScubaBoard Supporter ScubaBoard Supporter

    # of Dives: 1,000 - 2,499
    Location: Markham, Ontario
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    That is the way I make the initial check. If I get a zero reading I leave it at that but if I get a positive reading I then use the bag method where I place the unit in a ziplock bag and then run gas into it. The reason for this is that the unit is very sensitive to pressure and readings can be significantly effected by the rate of gas flow but with zero CO flow does not have any noticeable effect, it will still read zero.
     
    Angry Turtle likes this.
  3. Scuba-Lad

    Scuba-Lad Registered

    # of Dives: 25 - 49
    Location: Indonesia
    14
    3
  4. DandyDon

    DandyDon Old men ought to be explorers ScubaBoard Supporter

    # of Dives: 200 - 499
    Location: One kilometer high on the Texas Central Plains
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    New to me. Looks interesting. The O2 range is too limited to work as a Nitrox analyzer, but the CO specs look good, IF it's as good as claimed. I see it for $235 USD on one site, $149 on Ebay which makes me wonder why so much cheaper, what's wrong? As a tank tester, I'd want to turn it on, drop it in an empty ziplock bag, and fill the bag as carefully as possible then wait the required 30 seconds. Three cautions...
    1. You'll invariably suck in some outside air which could affect results;
    2. Even the best ziplock develop leaks quickly so start each day with a new one and carry a spare; and
    3. DO NOT crack the tank open after covering with the bag. I sent a bag and unit overboard that way once. Crack the valve to allow a slow escape, then place the bag over.
    If you get one, let us know how it works.
     
  5. Scuba-Lad

    Scuba-Lad Registered

    # of Dives: 25 - 49
    Location: Indonesia
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    Ah yes, I hadn't spotted the 30% max O2. Looking around at these multiple gas sensors, they all top out at 30% O2 so not useful as a Nitrox measurement tool. Looks like we are stuck carrying 2 devices round, one for CO and one for O2.

    With that in mind I'll probably just get a Nitrox analyzer and standalone CO detector separately. Would be nice to test a multitude of gases that may find their way into a scuba tank that could cause problems but I'm guessing CO is the most important (aside from O2 of course).
     
    DandyDon likes this.
  6. DandyDon

    DandyDon Old men ought to be explorers ScubaBoard Supporter

    # of Dives: 200 - 499
    Location: One kilometer high on the Texas Central Plains
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    Yeah, if you're diving Nitrox. I love it for square bottom profile wreck dives with a deco risk, but these days I'm doing multilevel reef dives and my air time sucks so I don't get anywhere close to deco anymore. I check for O2 at times when I'm on a boat with Nitrox divers just to confirm that I didn't get one of their tanks by mistake - which happens. I think it's healthy to be a little paranoid about what one is breathing at depth.
     
  7. D_Fresh

    D_Fresh ScubaBoard Supporter ScubaBoard Supporter

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    Any particular reason you would be concerned about being accidentally given a nitrox mix for an NDL reef dive? Just wondering

    Personally, I'd be cool with it, that's still less nitrogen and, some would say, more margin of safety if you're computer is still set to Air....
     
  8. RayfromTX

    RayfromTX Student Of Gas Mixology Staff Member ScubaBoard Sponsor

    # of Dives: 200 - 499
    Location: Cozumel while the cruise ships are gone
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    It depends on how deep you go. Dropping to 130 on 32% because you thought it was air might not turn out well for you. 36% would be even worse. Test every tank and get at least an idea of what you are breathing.
     
    D_Fresh and Ayisha like this.
  9. DandyDon

    DandyDon Old men ought to be explorers ScubaBoard Supporter

    # of Dives: 200 - 499
    Location: One kilometer high on the Texas Central Plains
    50,619
    5,670
    I've seen it happen. A couple of divers ordered one 36% Nitrox tank each to use on the second dive but unknowingly dove those on the first, deeper dive after not checking. MODs were exceeded.
     
  10. D_Fresh

    D_Fresh ScubaBoard Supporter ScubaBoard Supporter

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    @RayfromTX @DandyDon Good call, you're right. I just had shallow reef diving in mind when I read the post. But yes, it's totally possible to do a multilevel starting at 130, never get near NDL, and be limited by air supply. An unexpected nitrox cylinder would, indeed, be very bad news.
     

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