O2 Flush @ 19-23 ft / 6-7 m

[Heat Miser]

Some good comments ... and some interesting ideas

1) flush with a deco gas at depth ... I need to look at this after in the cold sober light of day ... after the margaritas have worn off. But I suggest an easier way I'll kill myself is to do an 02 flush at depth for long time.

2) I should have listened better in my course. .... Yep ..... I'm stupid and that's how I could afford a brand new rEvo last year ... because I'm stupid,

... Look at the below chart .... from the guru

1.5 PP02 Y AXIS does not line up (linearly - slope of 1:1) with 1.5 PP02 X AXIS i.e what is the tolerance ! what is the tolerance!

 

[Heat Miser]

Some good comments ... and some interesting ideas

1) flush with a deco gas at depth ... I need to look at this after in the cold sober light of day ... after the margaritas have worn off. But I suggest an easier way I'll kill myself is to do an 02 flush at depth for long time.

2) I should have listened better in my course. .... Yep ..... I'm stupid and that's how I could afford a brand new rEvo last year ... because I'm stupid,

... Look at the below chart .... from the guru

1.5 PP02 Y AXIS does not line up (linearly - slope of 1:1) with 1.5 PP02 X AXIS i.e what is the tolerance ! what is the tolerance!

View attachment 663929

So If I sold cells for a living... looking at above chart .... it doesn't get to 1.6 @ 6 m .... happy days sell more cells ....

 

[rjack321]

Specifically in the unit I have had 3 cells that where flooded twice (14 months old) and 1 cell once (8 months old) and 1 cell never (2 months old). Being paranoid and not having a pressure pot, I do a 02 flush at 6-7 meters after the majority my dives but at least once a month.
3 of your 5 cells have been flooded twice. I would replace these no matter what their performance.

If I’m doing the 02 flush @ 7m and only getting the 5 cell readings to spike to 1.55-1.57 should I be worried that I can’t get them to spike to 1.6 on O2 that reads 99.5% at surface.
this is normal, there are always some tiny amount of inerts in the loop when you are breathing it, unless you prebreath an hour and offgas all your natural N2 like you are prepping for a spacewalk.

I would get yourself a pressure pot but recognize that even a tiny variance in the analog gauge on the narced@90 pot gets you a ppO2 of 1.57 instead of 1.6

I find the dreams respond quickly to 02 flush, but I have my old cells in both of those dreams, and I have my newer cells in the shearwater petrel controller. The oldest cell (14 months and number 2) in the controller takes the longest to adjust but eventually 2-3 seconds get to 1.55.
I would not quibble about 2 second delays but if you are already doubting the cells (see 2x flooding above) then replace them

No cells - not even the brand new one hits 1.6. thoughts please

i.e what is the tolerance ! what is the tolerance!

View attachment 663929

3% deviation from linearity at the surface = 5% deviation at 1.6 = about 0.08 ppO2

Less than 0.1 ppO2 units which is why running at 1.3 for any extended period of time is dicey, true pppo2 could be 1.38. I do run at 1.3 for short wreck dives, once you start looking at 90-120 min dives its time to back off a bit more.

Your 1.55 or 1.57 is totally normal given all the vagueries in the system doing this while breathing

 

[Capt Jim Wyatt]

Your 1.55 or 1.57 is totally normal given all the vagueries in the system doing this while breathing

I agree.