Cis Lunar Mk 6

Tom Rose

Lots of nteresting comments...and a bit frustrating, I'l bet....In our discussion at DEMA, it was clear to me from your explanation that the unit was not a 600 foot dive unit but a sports diver unit and should be judged as such. Just looking at the size of it should have made that clear...It was to me.

While I may want to go on manual, bail out to oc at sports diving depths and times is an excellent alternative....well within the skill level of most OC divers who carry a pony bottle or spare air. I have always felt that the dive I am on is not nearly important as the dives I plan to be on the rest of my life.

Thus at the slightest sign of a gurgle or any any other failure, I bail.

Perhaps everyone should step back recognize the target audience for this system before jumping the gun. The bigger potential customer base is interested in rebreathers because:

1. They are lighter than OC or can be in sports models.
2. They do not make bubbles and scare small stuff they are trying to image.
3. The warm moist air on long dives
4. They are neat pieces of equipment.
5. Dives over an hour in the 130 or so foot range without twin tanks.

While they may be glad to sell almost everyone one, it is not the unit for many of the divers on this board....and the target customer group is not well represented.

I well remember a few years ago when you could almost know everyone diving a rebreather. Like any sports activities it is going from an extreme sport to mainstream. It is fun to watch.

Keep up the good work,
Tom

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The 50-50-90 rule: Anytime I have a 50-50 chance of getting something right, there's a 90% probability I'll get it wrong the first time.

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dave t

I agree Tom but already you are adding a bailout cylinder, you suggest a dive to 130ft for an hour! bail from that and you are in deco. Now we are getting closer to the skill levels of the guys on here!

Rich what happens if the validating cell starts to tell lies?

I assume the cells are r22's or such what is their maximum working po2? I was under the impression it was about 2.5bar!

Dave

TritonDiver

The new version is now uploaded.

Here's the direct link: http://www.poseidon.se/DL_files/MK6_White_Paper_v2.pdf

Richard Lundgren

Hi Tom

Good post. I fully agree that the first step in the problem resolution chain for any recreational must be to signal your team and then bail to OC. In fact this is how I dive my breather for technical operations too. Get on OC, then try to identify, solve and decide on what to do.

I doubt however that the displayed 3l dilluent bottle will be sufficient and would have opted for at least 40cf and a max depth about 30m instead of 40m. Small size is cool but any diver needs gas. In a OOG situation I fear that donating to a diver in need from a partially already used 3l tank will not do the trick.

Take care
Richard Lundgren

Drmike

exactly... and all our BOV are copies of CIS lunars BOV

Meg dsv is copy of Prism dsv which is copy of MK15 dsv which is copy of......I could go on but you get the point

__________________
Cave diving is a sport
Wreck diving is a sport
Diving in general is a sport

'Rebreather diving' is not a sport
its the delusional obsession with a highly dangerous and often inappropriate piece of equipment

Tom Rose

So true.....so true....an excellent point.

Tom

__________________
The 50-50-90 rule: Anytime I have a 50-50 chance of getting something right, there's a 90% probability I'll get it wrong the first time.

www.atlimp.com

Tom Rose

Probably right......but once again, the sports diver (read casual diver having his or her own type of fun underwater) is usually on a commercial dive boat with OC divers who are limited to some time at depth, and no decompression allowed, not an technical diving trip....all of us have been there...done that....and may still be doing it. I do not want to hijack this thread and may start another to discuss.....when in a dive do failures seem to happen?

Everyone should read the white paper...twice.

Safe diving,
Tom

__________________
The 50-50-90 rule: Anytime I have a 50-50 chance of getting something right, there's a 90% probability I'll get it wrong the first time.

www.atlimp.com

vidodivr

Richard Pyle Interview aka DeepReef

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Rob LaLonde
Rec and Tek Media, Inc.
Full Service Film and Video Production


CK #087, Narked@90 stand, URM

dave t

Rich

Am I right in assuming that all of the calibration and verification of the sensors starts with info from the ambient pressure sensor? if this is right how do you ensure the ambient pressure sensor is accurate enough for the calculations and can its accuracy wander?


What is the maximum depth you blow o2 over the sensor and is it only diluent from then on?


how do you ensure that the sensor only sees the "squirt gas" and that injected gas is not contaminated by the breathing loop gas? both sensor faces are in contact with the loop gas right?


thanks

Dave

jaap

Thanks for the replies Rich.

A few more questions:

How about the pos/neg predive tests? I suppose the unit could make a positive pressure test automatically. Does it do that? How about negative pressure?

Some more about the OPV's, is the final design only going to have the dumps we can see in the lower part of the lungs as OPV's? Would this not perhaps cause a risk of a runnaway ascent if the diver is at minimum loop volume and then ascends in a standing position? Of course this could be handled very easily manually by the diver. But is the idea not to make the unit as automagic as possible?

Like Dave I also wonder about the pressure sensor. Is there any redundancy or way of ensuring that is accurate (given its involved in the pO2-control system)?

/Anders

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My initials: JAAP