Where should I start to approach the rebreather world

Please register or login

Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.

Benefits of registering include

  • Ability to post and comment on topics and discussions.
  • A Free photo gallery to share your dive photos with the world.
  • You can make this box go away

Joining is quick and easy. Log in or Register now!

lermontov

Contributor
Messages
1,194
Reaction score
734
Location
christchurch
# of dives
500 - 999
back to the OP - and if you get a ccr you be able to join in all these fruitful discussions
 

tbone1004

Technical Instructor
ScubaBoard Supporter
Scuba Instructor
Messages
19,299
Reaction score
12,063
Location
Greenville, South Carolina, United States
# of dives
I'm a Fish!
@stuartv traveling so I’ll get caught up later. Point I want to make is that yes, people have died with Shearwaters due to voting logic. No shearwater configuration uses more than 3 cells on any individual computer so having 5 cells has no bearing on the voting logic.
 

Tassi Devil Diver

Contributor
Messages
324
Reaction score
198
Location
Tasmania, Australia
# of dives
1000 - 2499
On a standard scrubber stack you are probably throwing away 1/3rd of fresh scrubber after each fill. With rEvo rMs I can use pretty much all my sorb. I do this by having four scrubber canisters. After a bigger dive with two hours run time I usually have 2 to 2.5r hrs cycle time remaining on the top scrubber, my typical dives are 20-30 minutes at 50 -80m. I can do a second two hr dive to those depths again but I usually replace with a fresh canister if I am doing a similar dive the next day. I then use the partially used canister on a second dive, I will typically do a second dive to 30-50m with a 1.5hr dive time, after that dive would typically have less 1hr to 40min remaining on the scrubber, will then use this scrubber on a shallow NDL dive or I dump it if need for a bigger dive. I can make decisions about what I do with my scrubber based on real data, not some rule of thumb. I am happy to run the cycle time down to the last minute on the top scrubber canister making best use of all the sorb in that canister, I do this regularly in our scallop and lobster seasons on a 10-15m dive being the third dive on the scrubber.

In my area where water ranges between are 12-16C I would not do the 2 60m dives for 50min (run time 2:40) as challenged above, possibly in the tropics in 28+C water I can get 6hrs out of a single scrubber canister, after the first dive I would review the rMs data and make a decision about the second dive, but it would be possible.
 

Wibble

Contributor
Messages
2,234
Reaction score
1,809
Location
UK
# of dives
500 - 999
Fill one of your scrubbers with sorb and do the two dives mentioned earlier and then report back here.
Or stop making claims that your unit magically uses half the amount of sorb compared to others.

I'll wait.
You always throw away perfectly good usable scrubber because you simply do not know how much of your scrubber is consumed as you do not have a real-time scrubber monitoring system.

OIC. You’re recommending that I disable my scrubber monitoring system to prove what exactly?

Do you also advocate use of a ducking stool to test this?
 

Wibble

Contributor
Messages
2,234
Reaction score
1,809
Location
UK
# of dives
500 - 999
@stuartv traveling so I’ll get caught up later. Point I want to make is that yes, people have died with Shearwaters due to voting logic. No shearwater configuration uses more than 3 cells on any individual computer so having 5 cells has no bearing on the voting logic.
Hence @stuartv said to drop the setpoint to 0.7 to effectively disable the controller functionality — in the absence of any other way of turning off the injection of oxygen whilst underwate.
 

rjack321

ScubaBoard Supporter
ScubaBoard Supporter
Messages
11,797
Reaction score
6,841
Location
Port Orchard, Washington State
# of dives
1000 - 2499
Hence @stuartv said to drop the setpoint to 0.7 to effectively disable the controller functionality — in the absence of any other way of turning off the injection of oxygen whilst underwate.
You shut down the O2 valve if you really want it off - that's what an O2 boom is afterall
 

Wibble

Contributor
Messages
2,234
Reaction score
1,809
Location
UK
# of dives
500 - 999
You shut down the O2 valve if you really want it off - that's what an O2 boom is afterall
Yes.

However, the orifice will depressurise the O2 line and could result in the first stage leaking when re-pressurised.
 

tbone1004

Technical Instructor
ScubaBoard Supporter
Scuba Instructor
Messages
19,299
Reaction score
12,063
Location
Greenville, South Carolina, United States
# of dives
I'm a Fish!
Hence @stuartv said to drop the setpoint to 0.7 to effectively disable the controller functionality — in the absence of any other way of turning off the injection of oxygen whilst underwate.
Or dive a unit that lets you manually override the voting logic by disabling cells a la divesoft. 5 cells doesn’t make a unit any safer than 3 which in this case is not much better than 2. The Liberty gets a pass with 4 because each side has 2 which gives true redundancy but the O2ptima does not because it uses 3 on controller and 3 on readout but they don’t talk to each other.
 

Degenerate

Contributor
Messages
570
Reaction score
451
Location
EU
You always throw away perfectly good usable scrubber because you simply do not know how much of your scrubber is consumed as you do not have a real-time scrubber monitoring system.

OIC. You’re recommending that I disable my scrubber monitoring system to prove what exactly?

Do you also advocate use of a ducking stool to test this?
To prove your laughable claim that your Revo uses half the sorb of other units.

I really wish my AP would have some sort of way to monitor scrubber life in real time.
Oh wait, it actually does.

Not going to feed your trolling any more, you are obviously not getting the point and you are so certain that your Revo is powered by magical fairies that I can't see the point of indulging you further.
Again, I'm sure it's a nice unit but there is no magic in it.
 
https://www.shearwater.com/products/teric/

Top Bottom