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The European standard is EN14143, if you PM me your e-mail I can send you the pdf file.allenwrench:
CO2 is injected into the loop and the gas composition within the loop is measured. The allowed CO2 content is 5000 ppm, or 0.5% SEV.
It's not powder, actually powder or dust is something you really don't want in your loop. If that mixes with water you get a caustic cocktail.
Yes, semi-closed rebreathers like the Dolphin and Azimuth add gas constantly at a higher rate than what the diver needs. The difference is dumped out of the loop, hence semi-closed. Passive SCRs like the RB80 add gas with a mechanically triggered valve on every breath, dumping a metered amount the loss of which triggers the gas addition. Both types of SCRs use premixed gas(es). These units don't have any electronics whatsoever, although it can be argued that the addition of a pO2 monitor is a rather good idea.
caveseeker7:The European standard is EN14143, if you PM me your e-mail I can send you the pdf file.
CO2 is injected into the loop and the gas composition within the loop is measured. The allowed CO2 content is 5000 ppm, or 0.5% SEV.
It's not powder, actually powder or dust is something you really don't want in your loop. If that mixes with water you get a caustic cocktail.
The absorbant is dated by the manufacturer and has an expiration date. If the container is openend it needs to be resealed as the absorbant will otherwise react with the Co2 in the air and be used over time.
Yes, semi-closed rebreathers like the Dolphin and Azimuth add gas constantly at a higher rate than what the diver needs. The difference is dumped out of the loop, hence semi-closed. Passive SCRs like the RB80 add gas with a mechanically triggered valve on every breath, dumping a metered amount the loss of which triggers the gas addition. Both types of SCRs use premixed gas(es). These units don't have any electronics whatsoever, although it can be argued that the addition of a pO2 monitor is a rather good idea.
The KISS CCR use a combination of constant mass flow orifice and manual addition valve to add O2 into the loop. They don't have any setpoint control electronics or alarms. Only three O2 sensors connected by three cables to three monitors that allow the diver to keep on top of the pO2 in the loop and manually maintain the setpoint. Those rebreathers are quite popular, actually, and many hpmebuilders use like systems to either build their own rebreathers or convert SCRs to CCRs.
Once the original container is opened and sealed, the absorbant will react with the minescule amount of CO2 that it got in contact with. There is very little in normal air. Once that is absorbed the process stops.allenwrench:
That's really hard to answer as the preparation time varies considerably from one unit to the next. Just take charging the scrubber. The O2ptima is probably the quickest, using the Micropore cartridge instead of granular absorbant. Probably a minute or two. Filling the Sport Kiss scrubber takes me about 5 minutes, filling the PRISM scrubber about 20 mins.
caveseeker7:Once the original container is opened and sealed, the absorbant will react with the minescule amount of CO2 that it got in contact with. There is very little in normal air. Once that is absorbed the process stops.
To be honest I'm not sure how long an opened and resealed container could last ... just gotta make sure you dive enough so it won't expire.
That's really hard to answer as the preparation time varies considerably from one unit to the next. Just take charging the scrubber. The O2ptima is probably the quickest, using the Micropore cartridge instead of granular absorbant. Probably a minute or two. Filling the Sport Kiss scrubber takes me about 5 minutes, filling the PRISM scrubber about 20 mins.
Getting the PRISM ready to dive takes me about twice as long as the Sport Kiss, about an hour.
Then again, the PRISM lasts twice as long as the Sport Kiss, too.
I usually take my time and do it slowly and thoroughly. Doesn't seem to be the place to save a few minutes, and I enjoy doing it. Part of RB diving.
But the general setup is basically the same, fill and analyze tanks. Fill scrubber. Assemble unit and check for damage, fix or replace parts as necessary. Check valves, check loop integrity, check cells and calibration, electronics where applicable.
Immediate pre-dive checking valves and loop integrity again, gas content, breathing off the loop to check scrubber and warm up absorbant, raising pO2 to 0.7 ata. About 15 mins, during some of which (pressure tests) you can get your suit and ther gear ready.
In the water bubble check to make sure there are none.
Jeff Bozanic's "Masterring Rebreathers" has pre- and post dive check lists for a bunch of rebreathers in the appendix, including filling isnstructions for the scrubbers. Highly recommended reading for anyone intrested or diving a rebreather.
