Measure scrubber runtime?

[Wibble]

I believe that 1.35kg equals 3lbs not 4lbs.

Sorry, I got my maffs wong!

1.35kg is 3lbs of Sofnolime's finest. Or nice and cheap to run

 

[Tassi Devil Diver]

The same reason there is no temp stick in a Meg, Kiss, Triton, Optima, SF2, Hollis, RB80, and others. It's an unneeded complication.

Actually there is zero complication for the user. I would rather use RMS that gives me empirical data on scrubber usage than using rules of thumb and other guesstimates.

 

[jale]

Actually there is zero complication for the user. I would rather use RMS that gives me empirical data on scrubber usage than using rules of thumb and other guesstimates.

Are not empirical data a kind of rules of thumb or vice-versa? In RB diving at least

 

[Wibble]

Are not empirical data a kind of rules of thumb or vice-versa? In RB diving at least

The thing with the Revo RMS system is there's two scrubbers. There is an absolute measure which is the transition to the second scrubber, so the RMS can be "absolutely" benchmarked.

When you progress into the second scrubber, you could rely on the RMS, but the recommendations are that you have 45 mins more time on the second scrubber (certainly for planning).

 

[fsardone]

You can apply the same technique to a normal axial scrubber, just add a mesh filter in the middle of the scrubber with temp stick on the outgoing side.

I would advice against this ...
First it would be quite difficult to undo the top part of the scrubber without disturbing the rest of it unless you also add a retaining nut.
Second and most important the reacting section of the scrubber is function of gas density and, therefore, depth. It would be very difficult to determine that the lower half of the scrubber is unused. So you would dive with an unpredictable second half of the scrubber.
I am not a Revo cert diver, but I believe they do swap the filter so the number one is the first on the second dive and so they get warned if the new and surely unused second half of the scrubber start reacting. From that point on they have established data from manufacturer.

People should understand that diving rebs requires aviation mentality: preventative maintenance, corrective mantenance when needed and, especially, replacing parts either on expiry date or functioning hours (which ever come first not last) ... It is your life you are experimenting with!

My 2€c.

Cheers
Fabio

 

[uwxplorer]

I almost never dive without a bailout cylinder.

Wrong.

 

[uwxplorer]

Actually there is zero complication for the user. I would rather use RMS that gives me empirical data on scrubber usage than using rules of thumb and other guesstimates.

It's electronics. Dr Murphy tells us it will fail. If you have no backup plan, guess who is going to have some guessing to do?

 

[Gareth J]

Wrong.

Expand - I'm always looking to improve.

 

[flymolo]

This might be an oversimplification, but couldn't you use the amount of o2 consumed to calculate a rough estimate of co2 produced, and then compare that against the total co2 capacity of the scrubber media as indicated by the mfg test results?

http://www.divelime.com/dldownloads/Test_Data_Intersorb_812_v_Sofnolime_797.pdf

Edit: oh, I guess this is what the GUE method seems to imply.

 

[broncobowsher]

The problem I have with most arm chair scrubber calculations is they are based on 1 bar of ambient pressure. But diving adds a pressure variable.

Get down to the scrubber at the microscopic level. two molecules of sorb gapped so 100 molecules of gas (yes I am simplifying it by treating all gas molecules as the same size) fit between them. Go to 5 bar of depth, not you have about 500 molecules between those 2 points. This is where bed depth gets critical. A scrubber at the surface can run a very shallow bed depth. A scrubber nearly used up will still work on the surface. But get some depth, and you need more working scrubber to be in contact with the CO2 in the gas. That is simplified, I understand there are a dozen more variables and it isn't as linear as it sounds. But the general concept should be thought about when thinking of using a scrubber to the end limits.

A mostly used up scrubber will work fine in the shallows, but not at depth. Played correctly, this can be matched to deco profile. Played wrong, a CO2 hit.