Computer help

[buleetu]

hi everyone

were here in eygpt at the moment having a ball, just finished a dive about 1 hour ago

just before the safety stop my rented computer started beeping out of it and i thought perhaps i was ascending to fast but when i looked at it there was a 5%o2 saturation warning flashing i have never used a computer before and this was my third dive with it (computers are cool by the way, have to buy one soon) im fine with understanding everything else on it but im not sure what this warnings about
my instructor didnt expand very much on it when i asked him but said its fine dont worry

its an uwatec alladin computer can anyone help

thanks guys

seen my first glass fish today, about 20,000 of them or something hahahah amazing fish

 

[Doc]

About right now you're getting rested up for your second day of diving. It is 6:30 p.m. in Egypt, Saturday night. You've got about 4 more hours before the evening entertainment begins!

Barring a better explanation here that arrives before your boat departure in the next 12 hours- go to the dive shop and tell them to speak slowly and distinctly. Explain exactly what the computer was saying- and more importantly what you should understand as to its operation.

Are you in Sharm? What outfit are you diving with?

 

[scubadiver888]

There are quite a few different versions of the Alladin dive computer. If you know the exact model, the manual is available online at Scubapro.

Regardless, 5% o2 saturation sounds like an indication of your oxygen accumulation.

There are at least two possibilities. 1) the computer is set to Nitrox mode and you are diving air. 2) you are diving Nitrox.

If you are diving with air and the computer is set to Nitrox then all your nitrogen loading information is wrong. You should be able to get max depth and time from the computer and use your dive tables to calculate whether you have exceeded recreational dive limits. You should switch the computer to air mode if you are diving air. Personally, if my tables told me I exceeded the limits, I'd stay out of the water for 24 to 48 hours just to be safe.

If you are diving Nitrox, why don't you know what a 5% o2 saturation means? I'm not certified for Nitrox but I understand too much oxygen can result in oxygen toxicity. If you are diving with Nitrox (increased amount of oxygen to reduce the amount if nitrogen) you have to monitor your oxygen intake. I'm guessing that 5% is nothing to worry about but I would want to know what number should I start worrying about. If it is 100% then 5% is nothing. If oxygen poisoning happens at 10% then 5% is not great.

 

[buleetu]

thanks for ur reply

im diving 28% o2 air,not nitrox my computer is set to 21% o2 air

my instructor yesterday had the exact same reading on his computer when i asked him and he said we were fine, big OK, i really should know what to expect before it happens in the water though shouldnt i,
im diving with subex in sharm yes ,they seem fine, quiet reasonable pricing,nice people

we had a great time last night in naama and im still recovering so today is a rest day no diving for me hahah

 

[kadleck]

im diving 28% o2 air,not nitrox

Err, 28% O2 is nitrox! ... But then it sounds like your computer thing is OK. Strange that it mentions O2 at all when it's set for air though. Mine only warns about O2 when in nitrox mode (but it is a different computer, of course).

 

[buleetu]

ahh so i am diving nitrox then, how do they add the extra 7% to the air ??

o2 is toxic at a certain depth isint it,so is the computer telling me that o2 is building up in my body

 

[kadleck]

the odd thing here is that you get an alarm at just 5%. If you're definitely using an enriched mix (you say 28%), the computer needs to be set the same, otherwise it will not calculate correctly. Also, if you've not had nitrox training, you should be on 21%O2 (air), so this is a little confusing!

To answer your first question, they enrich the mix when filling the tank by adding oxygen. This has the effect of reducing the nitrogen percentage, giving longer bottom time. That's it in a nutshell. Could say more, but typing this on an iPod!

Again if correct, yes it is warning of O2 build up, but 5% is very low. Mine warns at 80% and 100%, and that has not happened yet!

 

[buleetu]

quote"If you're definitely using an enriched mix (you say 28%), the computer needs to be set the same, otherwise it will not calculate correctly. Also, if you've not had nitrox training, you should be on 21%O2 (air), so this is a little confusing!"

this 28% air thing is new i guess, when u said it was nitrox earlyer i went down to the centre to find out some more, they say its a mild nitrox mixture theres a q&a below about it if u have time to read it

im not nitrox trained at all, i didnt intend using 28% but thats all they have down there,no 21% they say its fine for a non nitrox diver to use this stuff, my instructor told me to keep my computer set to 21% for conservatisims sake
thanks kadlack

Guest-Interview with Prof.Dr.Dr. Dieter Seiler


A more detailed interview has been held with Prof. Dr. Dieter Seiler. As a medical practitioner and an enthusiastic diver, he was able to give us an interesting feedback after his first dive with SUBEX air28:

Thank you for taking the time to answer a few questions. Dieter. You just did your first dive with SUBEX air28. What do you think of offering a mixture of 28% oxygen and 72% nitrogen as a standard?

In my view, it’s an excellent idea! 28 percent of oxygen allow the more conservative diver to plunge into depths of up to 40 meters with greater safety without causing any problems. E.g. I prefer to do extended dives and those can be done with SUBEX air28 without difficulties. And certainly it is also advantageous to those divers who wish to do several dives per day.

Do you think it is sensible to dive with 28 percent of oxygen, but to keep using the diving computer with a standard setting of 21%?

Absolutely! With the settings adjusted to 21% oxygen, the safety factor is much higher and the risk of decompression is reduced at the same time.

In how far can the average diver benefit of using air28?

Divers who come here on holidays only have a limited number of days on which they can dive. With SUBEX air28, the guests can use their holidays to the fullest, for they can do several dives per day.

Which disadvantages do our guests have by using air 28?

I don’t see any disadvantages. Quite to the contrary, since the maximum diving depth is limited to 40 meters, the mixture with 28 percent of oxygen represents an additional motivating factor to heed to the depth limitations.

Do you think it likely that other diving centres will offer a mixture of 28% of oxygen /72% of nitrogen as a standard in the future?

I like the idea very much.

Your slogan for SUBEX air28?

“Mit SUBEX air28 im Tank, fühlst du dich wohl, SUBEX sei Dank!“ (with SUBEX air 28 in your tank, thanks to SUBEX, you feel great!)

Dieter, thank you very much for your time for this interview.

Article and interview of 1.4.2006
Michael Latschenberger
Base Manager,El Quseir

 

[kadleck]

Well, one lives and learns! Thanks for the info.

 

[buleetu]

is it really that new that u didnt know about it