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>You wrote: >> >>Hi Mike, >>The issue was and is the production of safe units. Odyssey has already >put >>them in the field, and has delivered completed units ...unfortunately >for >>Odyssey at TEK and DEMA, the shipment they had been planning on using >for >>display was too late out of production. > >Without casting any doubt on the Odyssey, this was at best a real >marketing blunder. Despite what *may* be better tradeoffs for a segment >of the diving community, you have to admit that not showing up with A >working unit gives an impression like vaporware or manufacturing >problems. In the worst case, an instructor could have been paid to show >up with a working unit. Other evidence to the contrary, it leads one to >question whether or not this is a fielded unit. It is easy to prove that RBC has fielded units. From the perspective of an end user, I would rather a rebreather company spend its time and money on making the unit safe, than having a brilliant advertising and marketing scheme. And sure, not having made arrangements to get an "already sold" unit back from the field, once they found that the company doing the assembly of the new units would not make the departure date for TEK & DEMA, was a marketing blunder....but I'll say it again, safety is not about glitz at DEMA. Safety and function will arise from good engineering, and are in NO WAY DEPENDENT ON MARKETING OR SALES EFFORTS. > >>The handouts which you must have seen clearly showed the enormous >difference >>in safety margins. >> > >Which safety margins are you referencing? I've read the web pages and >find an alternative configuration that has no more safety margin than >other units. When I referred to safety margins, I was talking about the safety concept of reliance on electronic PO2 control/alarms for closed circuit, active addition, versus the semi-closed system with its inherently much safer passive addition system and NO reliance on electronics. There is a large safety margin in doing a 300 foot dive on tables with a bottom timer and depth gauge, with multiple gases switches and profiles all planned out ahead of time, versus foolishly going down to 300 feet with only a dive computer to control your profile. For the same reason, eliminating reliance on many individual pieces of electronics, each with multiple point failure potentials, and relying instead on a far more predictable, action-reaction mechanical system, produces a much larger safety margin. This is evident form the papers, and will be evident to you should you demo the system. > > > >>Safety is superior in the Odyssey because it does not rely on >electronics >>which will potentially fail, and in so doing allow a diver to become >hypoxic >>should there be a gas addition failure. > >Every element in a diving rig has potential for failure. If we're >talking MTBF, then the electronics themselves will not contribute >significantly to the MTBF attributable to the mechanical components. >The FIT rate of semicondutors is substantially lower than any >mechanical component that I've reviewed. Of course, case fittings etc >can reduce SYSTEM reliability. Gee that sounds like a strong arguement for relying on dive computers. Funny thing, my BC is over 6 years old with thousands of dives on it, and not one failure to its mechanical system----I would not expect an electronic BC to fare so well. I think you have too much time in the office, proving theories on paper, and not enough in the water ;) > >>Mike, the "safe" method of knowing your PO2s is computing the desired >mix >>based on depth, and using these mixes. I would NEVER trust my life to > >>electronics ---electronic failures are far too common, even with good >dive >>computers (I'm sure you know what I mean here Mike ;) > >Can you give a citation for your claim of electronics failure? Henry, come on! Just look at Dive Computers, after all, they are made by many of the same people who will be making the electronics for the rebreathers. Would you like me to start a thread on rec.scuba and the tech list called : "Has your dive computer ever failed, and what brand was it?" Not to >get off topic, but if you fly, drive a car, ride a train, have many >different medical procedures, you ARE trusting your life to >electronics. I have never heard of a plane crashing due to electronic failure ? I have never met anyone who has had to bring there car to the shop to get the lousy electronic mess fixed??? I try to avoid dangerous places like hospitals, give me a 250 foot dive any day over them. Dan >Send mail for the `techdiver' mailing list to `techdiver@terra.net'. >Send subscription/archive requests to `techdiver-request@terra.net'. > > Dan Volker SOUTH FLORIDA DIVE JOURNAL "The Internet magazine for Underwater Photography and mpeg Video" http://www.florida.net/scuba/dive 407-683-3592
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