MK6 now launched....

Leewenhooke

Ha! When I was working on my SEL airplane in 2001, I took a 1.5 hour ride with a old retired doctor in his Ercoupe (no rudder modifications). They're beautiful planes and if you keep the aluminum polished, as this guy's was, it looks like a sleek fighter trainer or something. As you have well explained that is VERY MUCH not the case. When we took off the winds were calm, but by the time we were ready to land, we had a 10 kt crosswind, which might as well be 30 in that thing. You can't crab so you have to dip the wing into the wind and hope you don't have too much side-drift for gear to handle. We did two very scary touch-and-go's trying to get it down and finally stuck it on the 3rd try during a lull in the wind. I played it off like it was no big deal (I fly UH-60's for the Army) but inside, I was crying and wanted my mommy.

Jokes aside, I read the MK VI White Paper this week and I have to say Dr. Stone's logic behind the self-calibrating cells seems pretty solid. There ARE some potentially dangerous situations with 3-cell voting logic, and he suggested that if he were to make an expeditionary version, it would have an additional primary cell anyway.

I'm embarrased to say that I don't know as much as probably I should about the inner workings of head units. What do the homebuilt geeks and "smart guys" think of his 2-cell system? Comments aside about the this particular MK VI unit, Is this "self-calibrating cell" configuration the future of CCR's?

jepuskar

I have gone over all the information I can find on this rebreather and I can say as a recreational diver I am interested in this unit. It seems like it would suit the kind of diving I enjoy doing most.

I shall wait and see what kind of presence/support this has in the states...I'm sure I will atleast go test dive one as soon as possible.

J

jptaylor9

Based purely on reading the whitepaper, I get the feeling that this can occur below 6m. I think the point is that as the gas is directly onto the cell face, by the test solenoid, the volume required is small & won't materially effect the ppO2 of the overall loop volume.

I stand to be corrected

The whitepaper is an interesting read...

JT

henckell

I have been told from reliable sources that the unit only uses 100% O2 down to 6 m, and below that it uses dil (air) for validation.

I think it might be too complicated to mix (with accuracy) O2 and dil to continue validation above setpoint at depths below 6 meters, given the cells maximum specified limits.

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jepuskar

The white paper shows a diagram that has multiple gas injecting solenoids. Two of the solenoids, O2 and DIL both shoot a small volume of gas onto the O2 cell surface...as stated above which one depends on your depth.

Another solenoid injects O2 into the loop at a point away from the O2 sensor to make up for diver metabolism.

Ohh hell..its all right here..see attachment.

Attached Images

MK6_White_Paper_v2.pdf (232.7 KB, 56 views)

Gareth Ingham

The unit certainly requires a lot of faith in a software engineers ability to produce lines of code that are fail safe. I would hope and trust that the same level of reliability has been built into this software as say a hospital life support system. If they added active Po2 display it would surely ease many of the concerns. You would see the spike or the verification of PPo2 when the o2 cell is hit with a spray of 02 or diluent and then go back to normal loop PPo2.

The drying of the primary o2 cell seems like a good idea, i am not sure why they don't apply the same value to the second cell however if it is such a huge concern for the primary.