I have been diving with OSTC computers for a long time now and I have always been happy with them and with H&W. First I used to dive with a 2N, and later, as I was starting CCR diving, I sold it to upgrade to an OSTC cR to have a redundant deco and PPO2 reading. It is now on the latest firmware (V3.01)
Everything was fine, until a few month, when I started to have the impression that my cR makes "over deco" calculation...
With the same dive profile, same gas, same GF and SP changed at the same time, same speed ascent, it gives me more stops that any other computer (the AP handset, other H&W computers, Shearwater, Garmin MK1...). All other computers give me the same TTS and stops (as close as 1 or 2 minutes), but my cR gives me around 25 minutes more for a 90m x 15 min dive for example... There is no link with the O2 sensors reading, as it makes no difference when real PpO2 is used to calculate the deco, or when I use fixed Set Points (anyway, the PpO2 reading is accurate and very close to the PpO2 read on the AP handset).
Of course on « little dives » with air diluent, not too long and not too deep, I can see no deco time decreasing faster than on other computers, but it has no real effect on my dive. Maybe that is the reason why I did not immediately noticed the deco difference, which become greater as the depth and time increase (and the diluent gas changes to a richer in He) ?
Using it on OC dives too, I noticed the same thing : « no deco time » decreases faster, and TTS in longer compared to any other computer.
As I have the chance to live in the Carribean for a few years, I dive in hot and clear waters, then it is not a big issue (except my buddies eyes when I show them the time we will have to stay still at 6m when their own deco is finished
), but it will be when I go back to live in France, with colder waters !
I just can't explain that difference. Did I missed a setting (although there's only a few on cR, compared to other H&W computers), is there a native issue (what I really don't think, as I have heard of no other user complaining about that, unless someone who reads me can testify to that ?), or maybe an issue with ONLY MY computer? Does anyone know if there way to check it (hoping without sending it back to H&W if not absolutely necessary?)