Sensors: which gas shall I have in the loop when not in use?

[tbone1004]

I have this Divesoft fan and I use it. But sometimes a few days later.

Akimbo's statement tells me drying the cells does not have to be done immediately, at least that's my reading. Tbone's statement says the oposite. Well, drying immediately is probalby no mistake. If it helps? Anyway I am thinking about the idea of blowing some air through the loop. Just like the fan but without disassembly. I could unscrew the O2 hoose, add an air hose and blow some air into the loop for 12 hrs. What do you think about it?

This is taken directly from the Liberty Manual and I would recommend you heed their recommendations and is why I'm surprised this wasn't emphasized during your course.

As a general rule, it is necessary to dry out the water trap after every dive or at least at the end of the diving day. Detach the head, remove the scrubber cartridge, remove the water trap, and dry it with a paper towel. Use another paper towel, to dry the exterior surface of the cartridg

The head should be left to dry to ensure proper functionality of the oxygen and helium sensors. Helium sensors are sensitive to moisture and condensation. Since moisture can condense directly inside the sensor, it is vital to dry out your head properly after divin

This is important to ensure a long lifetime and functionality of your sensors.

In areas or periods with increased humidity, we strongly recommend using the DIVESOFT Head drying fan.

 

[Agro]

My he sensors do not work anyway, my service man was not able to fix the problem, I forget about them.

 

[Akimbo]

Akimbo's statement tells me drying the cells does not have to be done immediately, at least that's my reading. Tbone's statement says the oposite.

I'm not sure I would draw the conclusion that drying cells would not extend the life of the cell based on my statements. I can't think of any experiences that would indicate that or not. Certainly purging them in an inert dry gas would do both.

I was mainly indicating that high humidity (literally dripping off the pressure vessel) versus normal (50-60%) didn't make a perceptible difference, but low O2 percentage and constant PPO2 might also be a contributing factor. Consider my comments anecdotal data points.

 

[tbone1004]

My he sensors do not work anyway, my service man was not able to fix the problem, I forget about them.

Likely because they were not dried out fast enough after the dive and they do not sustain high humidity environments very well, certainly not for long periods of time. Leaving them in 100% RH for days on end will kill them rapidly.

Do not harp on that one piece from the manual though, the oxygen sensors are mentioned as well.

 

[doctormike]

Maybe this is an OCD thing that doesn't really have much of an impact on sensor life, but I also try not to leave the cells in high O2 environment for too long. When I build the unit the night before, the last thing I do is shut off the O2, switch the setpoint to 0.19 (so the solenoid doesn't fire) and breathe the loop down to 0.21 or close to it. And then switch it back to 0.7 before shutting the unit off...

And yeah, I don't leave a wet unit sealed up for too long...

 

[rjack321]

This is taken directly from the Liberty Manual and I would recommend you heed their recommendations and is why I'm surprised this wasn't emphasized during your course.

That's because there was no course.

 

[Jack Hammer]

That's because there was no course.

I disagree, i think he's taking a Self Help Internet Training course.

 

[Wibble]

Cells break. That's just part of the cost of rebreather diving.

However, you do need to take care of them to give them a happy life before they go to meet their maker. You don't want unhappy cells to break just before or during a dive. Makes for an unhappy diver too.

The big difference between open circuit diving and rebreather diving is that you have to take far more care of your equipment than you ever did with OC. This includes building it to a checklist and being exceedingly pedantic with every step. Cleaning up after a dive is critical too -- you just don't want all the microbial crap in your lungs.

So, when you get home and unload your car you have to set aside time to break the unit down and rinse out the loop and do whatever's recommended for your box regarding the lungs --- every rebreather's different.

In the case of the best rebreather, a Revo , this means opening it up, pulling out the cells and injector tray, wiping out the lungs and rinsing the cloth(s) and loop under a tap and squirting some disinfectant in. Then hang everything up to dry with the rebreather open to the air.

It is a bit worrying to see you write that you leave it for a few days before cleaning it. It just seems a little negligent and not giving the rebreather the love and devotion it needs: you upset it, it hurts you back.

As @tbone1004 says, you have to make time for it.

 

[Josh the diver]

I disagree, i think he's taking a Self Help Internet Training course.

the problem is I do not think he is taking the little advice he is given. If he did do a course he needs to redo the course.

I don't dive a rebreather and I know more than him!

 

[broncobowsher]

the problem is I do not think he is taking the little advice he is given. If he did do a course he needs to redo the course.

I don't dive a rebreather and I know more than him!

It's been mentioned, but he refuses to accept it.