Remember when you started with Rebreathers.

[rsingler]

Good comments! I think our disagreement is only semantic, then. To use your example, when you change your loop o-ring, even if you don't disconnect all the loop hoses, that puts both you and me back at the step that says, "assemble loop." Hopefully, with a correctly ordered checklist, every step above that is irrelevant to the repair we just made.

As a non-Poseidon RB diver, I have to ask how often that happens - that you end up running the automatic checklist more than once before you splash? Given the number of little things that I tweak before the first dive of the week after a rebuild, it would seem like I'd have to run my paper list before I ran my automatic list, if only to reduce frustration with the inevitable stop.

And apart from the solid state sensor and your growing enthusiasm for your automatic checklist, what do you like better about your Se7en over the JJ? When I was taught BOV repair as part of my Poseidon technician's course, I was not impressed by the strength of some plastic pieces that lock the BOV together.

 

[Sifossifoco]

I am a bit... autistic, so I surely take more than the average care assembling the rebreather and maintaining it. I generally do a first automated check when the assembly is completed before I get out of the house, and then turn the rebreather off (no prebreathing for this first check). If anything fails at this stage, i have time and tools to fix it. Then when I reach the diving site, I turn the rebreather on again, and do a second self test, followed by prebreathing (which is also automatically timed on the Se7en). The only way it fails at this point, if it passed at home, is if I do something silly such as forgetting the exhaust valve on the counter lung open during the positive pressure step. So far using this strategy i never missed a dive. Even at home, the most common reasons for failure are my mistakes, like forgetting to set the right gas on the computer. I had a defective o-ring once, but then again being autistic and with an aviation background helps in keeping these problems to a minimum. I still don't know for sure how it happened, but I did jump once with the diluent valve closed, which I suppose was because of the rolling on the boat, after all automated and manual checks were successfully completed. Untill then I only re-checked the O2 valve immediately before jumping, now I re-check both, but I miss the JJ stand...
In short, I feel that the automated check forces me to be more careful and strict. In my case, this completely agrees with my personality. I do understand that not every diver is willing to go through the checks at least twice, if not three times, before diving though.

 

[Sifossifoco]

I find hard to say that the Se7en or the JJ is better than the other. In my mind, they are both great rebreathers, but as I said the Se7en seems to adapt to my personality better. The BOV does feel a bit flimsy (I was told that the reason for so much 'cheap' plastic on the Se7en is a military requirement, as apparently they don't allow delrin), and I replaced the original Poseidon mouthpiece with a different one, much more comfortable. The solid state sensor is in my opinion a great improvement, and, I know this is highly controversial, I am a believer in the Poseidon validation algorithm. My Se7en has three sensors (only one of them solid state), but I would be comfortable with two.

 

[Chett L]

I have found the small plastic rEvo check lists to be perfectly fine, have been using it for nearly 500 dives, it is small and simple. I don't need to be able write on it, I am committed to using the check list each and every time.

Agreed!

 

[RainPilot]

As a non-Poseidon RB diver, I have to ask how often that happens - that you end up running the automatic checklist more than once before you splash? Given the number of little things that I tweak before the first dive of the week after a rebuild, it would seem like I'd have to run my paper list before I ran my automatic list, if only to reduce frustration with the inevitable stop.

When you're a newbie CCR diver, it happens enough to be irritating. Then, you stop being irritated when you realise each time that happens it is an error you made, with the potential of killing you.

To be clear, the full procedure takes less than 5 minutes. I haven't had a "oops, gotta restart" for a really long time, IF I have assembled the unit correctly.

Every time I have failed a check, I have been VERY glad it did...

 

[tbone1004]

Old thread, but I had it marked to read and am just getting around to it.

For pre-jump checks, just remember your 2's! Courtesy of Ted McCoy

Positive & Negative
O2 MAV & Dil MAV/ADV
Wing Inflator & Drysuit Inflator
Primary ppO2 & Secondary ppO2

Add in analyze O2& dil, and stereo left & right during assembly.

Obviously you may or may not have an adv, may or may not have a drysuit, and may or may not have a secondary ppO2 monitor, but that is really all you need.

Also, for the love of all that is holy, do NOT calibrate the thing every single time you assemble. Do your positive pressure check with O2 and validate calibration if you don't have a cal kit. If you do, then run the O2 flush to validate. If it's "close enough", then don't recalibrate. 0.96-1.04 is "close enough" in my opinion and not worth the risk of messing up a calibration. This is especially true on the pre-diveCAN Megs that require 2-point calibration that is super easy to mess up.