discrepancy between computers

[tursiops]

I had two ladies on a trip with identical computers and identical dives and identical wetsuits, for that matter. One of them had radically different NDLs. Turned out one of them had inadvertently set her computer on one level of conservatism. Set it back, all was well. It was very hard to find this problem; other than the different times, the only clue was one little "mountain" icon on the screen. I finally found it by laboriously going through all the screens and menus, side-by-side, looking for something different. that would be harder if the two computers were not identical.

 

[dumpsterDiver]

Hi Dumpster,

I'm confident you were running both computers on the same algorithm and with the same mix. My guess is that the more conservative computer has a malfunctioning altitude sensor and is computing the dive as being done at altitude rather than at sea level. This is actually how the conservative setting works also. The altitude sensor malfunction can be periodic so that the computer works normally at times but is overly conservative at other times. You can check for this problem by running dive planning on the two computers. The normal one will be on spec regarding NDLs as published in the owner's manual while the malfunctioning one will give short NDLs, perhaps matching the values in the manual if listed for running the conservative setting.

I had this problem several years ago with one of a pair of Pro Plus 2s. Oceanic gracefully replaced the malfunctioning computer with a reconditioned one even though the computer was well out of warranty. I would call Oceanic service and talk it over with them.

Good diving, Craig

Thanks
I will drag them out and try it.. Much better help than Oceanic has provided.. so far..

 

[Doug Krause]

I'm sorry I haven't jumped in sooner. As usual, the scubaboard community has jumped in with the possible explanations that I would suggest. There's one sure fire way to find out what's going on - give our tech support team a call, they'll be very glad to help and/or bring your computer in for evaluation.

 

[mrcandy]

My guess is that the more conservative computer has a malfunctioning altitude sensor and is computing the dive as being done at altitude rather than at sea level.

I have had this happen to an Atom 2 and also an Atom 3, so very plausible. One way you may be able to check: I believe all the Oceanic products will display their current altitude level. Unfortunately the screen/menu on which it appears varies from model to model so I can't tell you exactly where to find it on a Geo. At my home location this shows up as "EL2" since I'm at 3500 ft ASL.

Check your two DC's and ensure they are reading the same. It doesn't matter what the value is, it just needs to match. I believe the manual also contains a list of altitude vs display values if you wish to verify the actual EL code that is displayed.

 

[dumpsterDiver]

I just went through both Oceanic computers, We set them with the same FO2 and the no deco limits for a 32% were identical, except for 1 minute difference at one depth. This is comparing a veo 250 versus a veo 180 X... so this confirms that they are not in some weird altitude mode. Any ideas now?

 

[scubadada]

DD,

From your initial thread, it appeared the difference was much greater. The altitude sensor problem can be intermittent. I believe the computer checks ambient pressure when it is turned on and then uses that pressure (altitude).

This was my only unique contribution to the discussion, I guess Oceanic is going to have to help you out

Good diving, Craig

 

[dumpsterDiver]

Well I have a call into them for a few days now. They said they were very busy but would call me back ASAP. No messages, no return calls, I'm still hopeful they will provide some customer support....

 

[Bob DBF]

My original post explained the situation. my son's oceanic computer boots up records dive time and depth all correctly. We enter in the same notrox mix on two computers.. we descend to 80 ot 90 feet in 100 seconds and he has half the no-deco time I have on the other Oceanic computer.

It was so ridiculous he ended up with 15 or 20 minutes deco on the second dive while I had remainng no-deco time.. It is crazy, every other time I have had a computer fail, it reads error or something or fails to boot up, but this one doesn't do anything like that?

DD I had a problem like this and found that the nitrox mix needed to be set immediately before every dive, otherwise it reset to 21%. As I remember there is a way to change it to hold the nitrox mix between dives, but it has been a while since my last nitrox dive. Check the fine print in the manual.



Good Luck

Bob

 

[dumpsterDiver]

Well, I spoke to Doug Krause on the phone and after a discussion of the strange behavior of the computer, he asked that I send it in to his attention (which I did about a week ago). I'm hopeful that Oceanic will handle this problem for me.

 

[dumpsterDiver]

I'm still hopeful they will return my phone call (and computer). Oceanic has been analyzing it now for about 8 weeks or so..