[n2diving]

Quote: (Originally Posted by EBT)

Thats your call. I had a quick look at their site and still cant see any published test data. To be fair though, they're not alone in that respect.

You also won't find any test results for any other rebreather on any
absorbent manufacturer's website. The rebreather manufacturer
is the one that's going to publish that data, and as you point out
it's not there for most... however it is available for the O2ptima...
O2ptima Rebreather CO2 Test Results

[Dave Sutton]

Quote: (Originally Posted by n2diving)

You also won't find any test results for any other rebreather on any absorbent manufacturer's website.

Think we could keep this thread on topic for BTS reports? Spin off the various sub-discussions to their correct forums?




Best,

Dave

[n2diving]

[quote=trob09;104820]I suppose that depends on how you define "performance metric". Does that include recyclability? global availability? Price-per-dive? [quote]


I was speaking of in-water performance, but since you mention it...

Yes, the cartridge is equally environmentally friendly as granular, many would
say it's more so. On my last liveabord trip there was a fellow on open-circuit who was annoyed because the operator had not allowed his granular rebreather, and they had allowed my cartridge rebreather because in their opinion it was more environmentally friendly.

Yes, the cartridge is equally available globally. I just shipped a keg of Sofnolime to California via Next Day Air, shipping was more than the value of the sorb. If the poor soul had wanted an equavalent amount of cartridges, the shipping cost would have been much less.

Yes, the cartridge does have a lower cost per dive than granular. It depends on how you dive. At retail prices, my cost per dive for the cartridge in my O2ptima is several dollars less than my cost per dive for Sofnolime in my Inspo Classic. I typically do four to six one-hour dives on my cartridge, I'm uncomfortable exceeding three to maybe four dives on the granular. I can also remove, store and reload cartridges, something I can't do with granular. This feature allows me to get maximum use of cartridges by rotating partials out and back into the canister, as appropriate for the dive planning. However, if I were to remain within manufacturer recommended durations, the cartridge would cost $2 more per hour of diving. To 'balance the budget' I could drink a couple less of those carbonated beverages my sister fusses at me about anyway.

All this is debatable but it's hairsplitting, the point here is that it's not at all clear cut that one type of absorbent is better than another.... it depends on the individual diver and their requirements. Some people (mostly cartridge users) feel the cartridge works best for them.... some people (mostly granular users) feel that granular is better for them... and in the few cases where I have talked to people who regularly use both, they generally prefer the cartridge because of the ease-of-use.



Perhaps some nice admin could split this over to the O2ptima or absorbent forum...

[trob09]

Quote: (Originally Posted by n2diving)

the point here is that it's not at all clear cut that one type of absorbent is better than another.... it depends on the individual diver and their requirements. Some people (mostly cartridge users) feel the cartridge works best for them.... some people (mostly granular users) feel that granular is better for them... and in cases where I have talked to people who regularly use both, they generally prefer the cartridge because of the ease-of-use.

Thank you for proving my point, which is quite a bit different from your earlier comment of:

Quote: (Originally Posted by n2diving)

As a general statement, there now appears to be no performance metric that you can apply to granular and cartridge in which the granular would outperform the cartridge... and it appears that there may be several performance metrics where the cartridge outperforms granular.

I could go on about "equally applicable in a MK 15.x, 'boris, etc.." which could also be determined a "performance metric".

If all you'd said was the top quote, I'd have no issue. You like what you like. Cool. When you start to say "no performance metric", my BS meter comes out.

[caveseeker7]

Quote: (Originally Posted by n2diving)

Yes, the cartridge is equally environmentally friendly as granular, many would say it's more so.

Do these many have any suggestion what to do with the used cartridge?
There's some sort of plastic grid in there, isn't it? Receycle? Send it back to Micropore for a refundable deposit?

Quote:

Yes, the cartridge is equally available globally.

Meaning you as a retailer ship it globally?
I know my LDS stocks DiveSorb, but surely doesn't have any cartridges.
Just where in Germany can I get them?

[caveseeker7]

Quote: (Originally Posted by n2diving)

Yes, the cartridge does have a lower cost per dive than granular. It depends on how you dive. At retail prices, my cost per dive for the cartridge in my O2ptima is several dollars less than my cost per dive for Sofnolime in my Inspo Classic. I typically do four to six one-hour dives on my cartridge ... However, if I were to remain within manufacturer recommended durations, the cartridge would cost $2 more per hour of diving.

It all depends just how far you're willing to exceed manufacturer's specs, and what rebreather and absorbant you compare it with.

The case of 4 cartridges goes for $129, so a fill is around $40. Dive Rite rates the Optima to 3 hrs in warm water, that's about $13/hr, correct? Less expensive if you dive past the rating, of course - unless you go too far and pay the ultimate price.

May be favorable to some unit/absorbant combinations, but take the PRISM with manufacturer recommended Sodasorb for example and the equation changes quite a bit. $99/pail, 6 fills from that means about $17/fill. Manufacturer rating for cold water is 5 hrs, so we're talking less than $3.50/hr.

All depends what sample you pick.

[trob09]

Quote: (Originally Posted by caveseeker7)

All depends what sample you pick.

Thus the Samuel Clemens reference....

[Dave Sutton]

Quote: (Originally Posted by n2diving)

I'm thinking April 1st is right around the corner.... I put the idea out there just as a blue sky.... I don't know anyone who's actually done it and if anyone claimed to have done it, I would want video proof.

I cannot for the life of me remember the guys name, but he was a Dive Rite guy who has left to go work for Micropore. He was with Tom McKenna at BTS and we were talking about the scrubber for the new little 02 rebreather I'm designing for my "customer". In any case, discussion went to the "underwater change" topic and he gave me the skinny. He said that he took off the rig, placed it on it's side, and opened up the scrubber and removed the old cartridge. He had placed the new one in a plastic bag, all the air sucked out, and had spun the bag to seal it. He placed the "ass" of the bag against the now open cartridge bay, "un-spun" it, and squeezed the cartridge home, closed up the rig, cleared it, and pressed on.

This was, my guess, just a "play session", sort of like me opening up the faceplate of a Mark-5 deep sea helmet while in the demo tank at BTS a few years back and eating a bananna underwater... no practical value, but fun anyway.

Dave

[Dave Sutton]

Quote: (Originally Posted by n2diving)

All this is debatable but it's hairsplitting, the point here is that it's not at all clear cut that one type of absorbent is better than another.... it depends on the individual diver and their requirements. Some people (mostly cartridge users) feel the cartridge works best for them.... some people (mostly granular users) feel that granular is better for them... and in the few cases where I have talked to people who regularly use both, they generally prefer the cartridge because of the ease-of-use.

Agreed 100%.

The day that they build a "drop into a Mark-15 can" cartridge is the day smile... but they never will, not sufficient market. Too bad.

The big thing for me is it's water resistance. It's not as good as a hydrophobic membrane, but it's pretty darned good.

Ideally, a rig should be able to accept either. It's only a matter of time before someone makes up a powder can for the Optima.. betcha.


Dave

[AD_ward9]

Quote: (Originally Posted by caveseeker7)

Do these many have any suggestion what to do with the used cartridge?
There's some sort of plastic grid in there, isn't it? Receycle? Send it back to Micropore for a refundable deposit?


Meaning you as a retailer ship it globally?
I know my LDS stocks DiveSorb, but surely doesn't have any cartridges.
Just where in Germany can I get them?

We have a pallet we are trying to sell (it has the small centre section, and we use a large centre section). Shipping from UK to Germany is cheap (www.postvan.com), and no taxes of course. We will match any US price.

On the recycling, the amount of plastic is tiny: a few percent. It can be buried.

Alex