Re: Subsurface mobile general question

On 2021-11-16 20:43, Robert Helling wrote: thanks a lot for those files. My model only involved the total O2 and diluent use, so I don’t need those pressures as a function of time. A ok. Here is what I found: The data scatters quite a bit over the dives and that does not get better using the

Re: Subsurface mobile general question

Hi, > On 16. Nov 2021, at 17:29, Paul-Erik Törrönen via subsurface > wrote: > > > These should have a simple down - bottom time - up-profile: > https://poltsi.fi/Sukeltaminen/ccr-logs.tar.bz2 > > > A bit of explanation about the content. The

Re: Subsurface mobile general question

On 2021-11-15 22:43, Robert Helling wrote: yes, let’s give it a try with some real dives. Would you mind sharing some CCR logs with me that have depth information as well as initial and final O2 as well as diluent pressures? Ideally some that don’t have excessive jo-jo phases with excessive buoya

Re: Subsurface mobile general question

Poltsi, > On 15. Nov 2021, at 17:58, Paul-Erik Törrönen via subsurface > wrote: > > Well ugh, you went to log so I can't tell anymore (my math-skill is crap > nowadays), but since you essentially have a model here, then one way to test > this would be to run it with input data of depth and me

Re: Subsurface mobile general question

On 11/15/21 13:53, Robert Helling wrote: So my guess would be that during the ascent you dropped f times the amount of diluent used during the dive of O2 that was coming from the O2 cylinder. So, to find the metabolic O2 consumption, that should be subtracted from the gas use from the O2 cylind

Re: Subsurface mobile general question

Hi Poltsi, > On 15. Nov 2021, at 12:18, Paul-Erik Törrönen via subsurface > wrote: > > So ~21min 30s during which the O2 cyl (2l) pressure dropped 25bar (50l). My > metabolic rate for O2 consumption during the bottom time was ~0.6l/min so > that means that I vented out about 46l of O2 during

Re: Subsurface mobile general question

On 2021-11-15 11:33, Robert.Helling via subsurface wrote: this is clear. I was asking to get an understanding how bad the error is to ignore that O2 is not only contained in the O2 bottle but also in diluent. Well the thing is that you really do not consume any of the O2 in the diluent. The

Re: Subsurface mobile general question

Robert, On 15-11-2021 10:33, Robert.Helling wrote: Jan, On 15. Nov 2021, at 09:11, Jan Mulder via subsurface wrote: The idea that there is a ratio between diluent use and O2 use is flawed. The main driver for O2 use is time and workload, and for diluent its the dive profile. this is

Re: Subsurface mobile general question

On 15 November, 2021 - Robert.Helling via subsurface wrote: > Jan, > > > On 15. Nov 2021, at 09:11, Jan Mulder via subsurface > > wrote: > > > > The idea that there is a ratio between diluent use and O2 use is flawed. > > The main driver for O2 use is time and workload, and for diluent its th

Re: Subsurface mobile general question

Jan, > On 15. Nov 2021, at 09:11, Jan Mulder via subsurface > wrote: > > The idea that there is a ratio between diluent use and O2 use is flawed. The > main driver for O2 use is time and workload, and for diluent its the dive > profile. > > this is clear. I was asking to get an understand

Re: Subsurface mobile general question

On 15-11-2021 08:33, Robert Helling via subsurface wrote: As a ball park approximation, many CCR dives (up to 65m) are done using air as a diluent, supplemented with oxygen from the O2 cylinder to make up for oxygen consumed as well as for higher O2 levels during shallower deco. But what

Re: Subsurface mobile general question

Hi Willem, thank you for your comments. > On 15. Nov 2021, at 08:18, Willem Ferguson via subsurface > wrote: > >> >> I meant more the other way around: If you diluent also contains O2, you >> underestimate the O2 consumption if you only use the pressure drop in the O2 >> cylinder. > The O2

Re: Subsurface mobile general question

On 2021/11/15 00:07, Robert Helling via subsurface wrote: Hi Poltsi, On 14. Nov 2021, at 22:44, Paul-Erik Törrönen via subsurface > wrote: When CCR, you're mainly interested in the consumption of O2 as noted previously. The diluent is not really tell

Re: Subsurface mobile general question

Hi Poltsi, > On 14. Nov 2021, at 22:44, Paul-Erik Törrönen via subsurface > wrote: > > When CCR, you're mainly interested in the consumption of O2 as noted > previously. The diluent is not really telling since it is mainly a function > of your profile as you use diluent to equalize the pressu

Re: Subsurface mobile general question

On 2021-11-14 05:01, Robert.Helling via subsurface wrote: OK, that guess was wrong. Our SAC calculation does not notice it’s a CCR dive. That is of course wrong. Created a PR that makes us refuse to compute a SAC for CCR dives. When CCR, you're mainly interested in the consumption of O2 as note

Re: Subsurface mobile general question

> On 14. Nov 2021, at 03:42, Robert.Helling via subsurface > wrote: > > my initial reaction is that there shouldn’t be a calculated SAC value for > rebreather dives. Or at least, if we computed something for O2, that should > be a completely different calculation as it would be independent o

Re: Subsurface mobile general question

Hi, > On 14. Nov 2021, at 02:40, Dirk Hohndel via subsurface > wrote: > >> Based on my manual calculations (discounting compresability and assuming >> ideal gas laws), I calculated 1.13 l/min but, Subsurface is showing 3.3 >> l/min. >> >> I am normally around 0.65 L/min but, I did an O2 flus

Re: Subsurface mobile general question

Sending anything with the exception of cloud backend stuff to "only me" is really not helpful. I cannot possibly do support by myself for an app with at this point about twenty thousand active users... > On Nov 13, 2021, at 2:16 PM, rick.warren4 wrote: > > I have a general question on SAC and r