Genesis computer variability?

[WOODMAN]

I started with Genesis computers, and have stayed with them despite a plethora of newer, more expensive types available out there. I guess I don't mind the 'hockey puck on your wrist' look which so many people seem to dislike. They have been easy to use and read, and battery changes are pretty simple and straightforwards. We accumulated three of them, an old React which resides in my console as a backup, and an old Resource for me and a newer React Pro for my wife. I decided to trade in my old Resource for a newer one, primarily to get the safety stop timer (which my wife's React has and which I had been coveting...), and did so through my local shop. The new Resource worked fine, and the timer was great, but I noticed that the new one was considerably more conservative on nitrogen loading that either one of the other two. They were all exposed to the same dives, and nearly the same depths, but the new Resource consistently accumulated nitrogen faster than the older two. On my last trip, the new Resource almost had me in deco (right on the edge..) while both my console React and my wife's newer React were still not quite in the caution zone. ??? So, when we came back, I had the Resource looked at by the shop I got it from. Worked fine, they said, but did seem a little more conservative. They started digging into this a little more, and consulted with the factory. They then started testing a few of the same units which they had for rental, and lo and behold, they ran into a few more cases of this variability. Genesis became very interested, and now the whole works looks like it is going back to the factory for analysis. I will try to keep you posted on what is going on. Anyone here encountered anything like this? Woody

 

[WOODMAN]

Well, this is still dragging on. The computer went back to Genesis (now Sherwood), and they monkeyed with it, along with 6 other ones that the dive shop sent with it. It came back recently, but still had the same problem. The dive shop is still wrangling with them, and its a good thing my next trip is not for a few months yet, so we have time for this little drama to play out. I will let you know as I hear more. Woody

 

[Graeme Tolton]

I have a react pro... I have been on dives where it will give me a few mins of deco when my dive partners with other computers will be well in the clear. These dives have been both on air and nitrox. I have also been on other dives, where my NDLs correspond exactly with my partner's computers. How signifigant of a difference is it?

 

[widget]

I am quite interested to hear the outcome here Woodman. Generally I find most computers will give a slightly differant reading on a dive in open water, the only real way to test them is in a chamber with a calibrated depth gauge, which I assume has been done here?.

Generally manufacturers will allow a small, acceptable (to them ) margin of error between units, but if there is a wild differance between random units when tested in a chamber it would be interesting to know possible reasons why this "could" occur.

 

[scubadada]

The computers may be setting the dive for altitude rather than sea level. This would result in a more conservative calculation of NDL. Use the planning function to check the NDLs at sea level to check whether you are getting the NDLs you should. The owner's manual may have a table of expected NDLs or you can check it against an identical computer that is known to be functioning normally. This problem may be intermittant and give you the problems with service diagnostics.

If this is the problem, the computer may be recalibrated or may require replacement. Best of luck with your problem.

Good diving, Craig

 

[NCadiver]

scubadada is correct, check out page 69 of your manual.

 

[WOODMAN]

Well, Scubadada nailed it. I just got back from the dive shop, and they said the computer was accessing a high altitude setting, and it appears there was no way to alter this. All 6 of the computers being examined were doing this, but the manufacturer can find no evidence of any others in their investigation. We still don't know why these were doing this, and the manufacturer still has them. They did kick me out a new 2009 model of the same computer, and my dive shop says it tests normal. So there you have it. I will test out the new computer myself when we visit Old Providence Island in early March, but I anticipate no trouble. Just another day in the fast lane, I guess. I really must commend my dive shop, Air Down There Scuba in Mpls, Minn. for their diligence to running this to ground for me. I wonder if I would have gotten service like this from a mail order house? Cheers- Woody