Question Dive Rite O2ptima CM & Europe questions (Usage, as well as the wretched CE)

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makar0n

makar0n

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Hi,

What's 7) a carbon tank? and secondly are you asking in 8) has anyone jury-rigged a CMF in the chop?

I have very limited experience on rebreathers (150 hrs) my amateurish view:

+'ve, the chop seems to trim out much better than a rEvo, -'ve, the WOB on the chop is not as good (in my non-CE test approach - opinion), but may be similar if lungs are held high on chest/in front of chest (i.e. super-manning). +'ve, Donning and doffing the chop is better. +'ve: Building the chop seems to be faster. -'ve: The chop doesn't have RMS -'ve: the chop doesn't have dual scubbers. -'ve: the Chop is a Dil-out solution so you cant save money on cheaper Nx bailout. I.E. Dil pp02 = Bailout pp02, whereas rEvo Dil pp02 <= Bailout pp02. -'ve: Durability rEvo has Titanium case Chop has canvas. Finally +'ve, +'ve the chop can adapt to to your current O/C style be it Singles, Doubles, Sidemount, simply by clipping on the front of d - rings, travelling is a breeze.

Regards, G

So for 7) meant carbon fiber tank..i.e. instead of alu/steel. These are apparently way lighter (so better for travel) but problematic when testing time comes plus have different buoyancy or so...

Eeerm, apologies my noobnes but what is CMF? :) What i meant in 8 was to put the leaky valve/needle (or however it is called, ie. same as in mCCR).

And thanks for feedback - travel and the general ease is exactly my goal. Curious about the WOB, do you make much diff being horizontal vs upside down? (i am often hanging head down when hovering above the critter, actually sort of my preferred position)

Aren't all chest-mounted rebreathers harder WOB than backmounted? Simply because the pressure is greater underneath your lungs that above them.
Ha, that is a question. Found a CM review around this forum, somebody took it down to about 140m or so, and said WOB was supposedly great.

It looks like there are instructors in Germany and Poland. They may be able to help you with your questions


Thanks. Already in touch but turns out the PL is not yet certified in CM, and the German one is really in Canada.
Anyways, got hold of some more "exotic" ones as might be i fly there to do the deed after all :wink:
 

Heat Miser

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So for 7) meant carbon fiber tank..i.e. instead of alu/steel. These are apparently way lighter (so better for travel) but problematic when testing time comes plus have different buoyancy or so...

Eeerm, apologies my noobnes but what is CMF? :) What i meant in 8 was to put the leaky valve/needle (or however it is called, ie. same as in mCCR).

I don't know about carbon fibre tanks ... seems feasible .... can you put 100%O2 in them? A Google search said Air only but I wouldn't take that as gospel

Yes a CMF (Constant Mass Flow) is another name for a leaky valve ... I'm not certain you need one if the solenoid on the unit is working.
 

Wibble

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Yes a CMF (Constant Mass Flow) is another name for a leaky valve ... I'm not certain you need one if the solenoid on the unit is working.
There's some "hybrid" rebreathers with both a CMF and a solenoid. The benefit is far fewer solenoid injections because the PPO2 doesn't drop as quickly due to the CMF constantly injecting the base amount of oxygen. If you're calm and relaxed it can be several minutes between solenoid injections, or you can manually run the rebreather.

The Revo is an hCCR.
 

Heat Miser

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There's some "hybrid" rebreathers with both a CMF and a solenoid. The benefit is far fewer solenoid injections because the PPO2 doesn't drop as quickly due to the CMF constantly injecting the base amount of oxygen. If you're calm and relaxed it can be several minutes between solenoid injections, or you can manually run the rebreather.

The Revo is an hCCR.
Yes, the ppo2 on the choptima bounces around abit because of the solenoid, on the revo there appear to be a few less spikes because of the combination of CMF and solenoid.
 
OP
makar0n

makar0n

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I don't know about carbon fibre tanks ... seems feasible .... can you put 100%O2 in them? A Google search said Air only but I wouldn't take that as gospel

Yes a CMF (Constant Mass Flow) is another name for a leaky valve ... I'm not certain you need one if the solenoid on the unit is working.
Well, seems not officially but apparently it works...just the servicing proves next to impossible apparently. Och well, maybe that is not such a swell idea after all :D

Aaach i thought i heard that CMF somewhere. Yeah that is exactly what i was thinking, more like to have the solenoid only operate when needed ie when leaky thingie is not enough. But for now more curious than anything, as guess that would mean unit is modified and that is a no no from insurance perspective (at least till it gets CE one day i hope)
 

Superlyte27

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Who services their rebreather annually? Lol
 
https://www.shearwater.com/products/peregrine/

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