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Thankyou! My point exactly! :) Nick & Wendy wrote: > >X-From_: owner-techdiver@aquanaut.com Fri Apr 09 19:20:58 1999 > >Errors-To: owner-techdiver@aquanaut.com > >Subject: Re: Trimix Question > >Date: Fri, 9 Apr 1999 18:45:28 -0400 > >x-sender: cobber@ma*.ci*.co* > >From: Jim Cobb <cobber@ci*.co*> > >To: "Jeff Waugh" <jrwaugh@ix*.ne*.co*> > >cc: "Steve Hogan" <Steve.Hogan@tr*.co*>, <pdisler@io*.ne*>, > > <silent@cu*.ne*>, "Tech Diver" <techdiver@aquanaut.com> > > > >Jeff- > > > >Sounds to me like you need some "screw-top brain therapy" :) > > > > Jim > > > > I'd go with the fins because when you simlify this gas mix problem it > becomes very clear that rolling isn't very effective without the fin > modification. Simply: look into a tall glass of ice water while you turn > the glass...the water remains in place. I suspect the coefficient of > friction with liquid on a flat surface is greater than with gas. KISS I > guess perhaps if you could rotate the tanks at a couple hundred rpm, you > may get some significant friction and mixing but that may be more difficult > than waiting a few minutes for the molecular movement to do the work for you! > > Nick > > >Sender: Jeff Waugh Date: 4/9/99 3:13 PM > > > >>Yes Jim, that is correct. In fact, I pulled the directions for > >>installation off of > >>your web site. > >>1) Cut top of cylinder off with a die-grinder or other suitable cut-off tool > >>2) Insert "Fin" mechanism gently into cylinder > >>3) Replace top of cylinder, making absolutely sure you have the grind > >>marks left > >>from the removal process lined up to facilitate a proper "bond" when the > >>welding is > >>complete. > >>4) Overfill cylinder by no less than 1500 psi. to ensure that the welding > >>process > >>yielded no leaks. > >>5) And last but not least, roll cylinder around garage to test your new > "Fin" > >>mechanism. > >> > >>Another fine product that will ensure that you DIR! :) > >> > >>Jim Cobb wrote: > >> > >>> The inside of my tanks are smooth, and would impart no stirring action to > >>> a mix. Did you weld fins inside your tanks to accomplish this mixing > >>> action you say rolling tanks does? > >>> > >>> Jim > >>> > >>> Sender: Jeff Waugh Date: 4/8/99 11:13 PM > >>> > >>> > I'm not sure about the temperature actually being that much of an > >>> >influence > >>> >on the ending reading. I have found that generally low O2 % mixes such as > >>> >"deep" > >>> >Tri-Mix'es generally homogenize to the final desired analysis over a > >>> >period of a > >>> >few hours. > >>> > I've found that high O2 mixes that if filled with O2 and topped with > >>> >air and > >>> >allowed to sit without agitation, can render an inaccurate analysis a day > >>> >later. > >>> >At that point, a simple "roll" around the garage will suffice to get you > >>> >what you > >>> >were looking for! > >>> > > >>> >Jim Cobb wrote: > >>> > > >>> >> I don't know about you guys but I think the problem we are dealing with > >>> >> here is the temperature of the mix rather than stratification. As > the mix > >>> >> cools off the reading becomes more accurate. > >>> >> > >>> >> Jim > >>> >> > >>> >> Sender: Steve Hogan Date: 4/8/99 6:53 PM > >>> >> > >>> >> > > >>> >> >I have run into this and have modified my mixing procedures > >>> >> >so that after I add the O2 to the helium I wait 1 day (I > >>> >> >usually mix at night so waiting around is not appealing) > >>> >> >before measuring the O2 % (O2 & He). It is not hard to figure > >>> >> >out what percentage I expect after mixing O2 with He. > >>> >> >Next step is to add air, wait a few hours (usually doing > >>> >> >something else) and then measure again. > >>> >> >I fill about 50 psi/min so I expect to not get much mixing from > >>> >> >Brownian motion. > >>> >> > > >>> >> >Steve > >>> >> > > >>> >> >-----Original Message----- > >>> >> >From: Patricia Disler [mailto:pdisler@io*.ne*] > >>> >> >Sent: Friday, April 09, 1999 1:14 PM > >>> >> >To: S I L E N T I M M E R S I O N > >>> >> >Cc: techdiver@aquanaut.com > >>> >> >Subject: Re: Trimix Question > >>> >> > > >>> >> > > >>> >> > > >>> >> > > >>> >> > > >>> >> >At 09:16 AM 4/8/99 -0700, you wrote: > >>> >> >>Frank, > >>> >> >> > >>> >> >>>Not me, but I do let the filled tanks rest a day before > analyzing. An > >>if > >>> >> >>>you want to tell me > >>> >> >>>thats not neseccary I recommend that you try this: Fill oxygen, top > >>with > >>> >> >>>air, wait a minute, > >>> >> >>>analyze mix, turn the tank so that the valve faces ground, wait > >another > >>> >> >>>minute and than > >>> >> >>>re-analyze the mix. > >>> >> >> > >>> >> >>And it's the same... or not? > >>> >> >>When filling a tank the temperature and pressure are high which in > turn > >>> >> >>gives a high diffusion coefficient. Makes the mix homogeneous almost > >>> >> >>instantaneoulsy (couple of seconds). > >>> >> >>What kind of differences do you get? > >>> >> >>What kind of analyser do you use, are you sure the hoses are drained > >>when > >>> >> >>using a regulator or something? > >>> >> >> > >>> >> >>Regards,> > >>> >> >>THOMAS > >>> >> > > >>> >> >I have witnessed Nitrox mixtures take a while to fully homogenize. > >>Several > >>> >> >years ago while mixing 80/20, (Yeah I know don't start) it came out > 63% > >>O2 > >>> >> >approx 30 min after the very s-l-o-w top off to fill pressure. Yes I > >>> >> >checked the calibration of the aynalizer (Teledyne TD-50). Each time I > >>> >> >would check the O2 reading would climb. I did this over a period of > >>several > >>> >> >hours. Later it was right on 80%. > >>> >> >I'd have to say stratification can and does occur, esp. if there is > not > >>> >> >enough turbulence during top off. > >>> >> >I have never seen this with Trimix as the fill rates are much higher. > >>> >> >However I suppose it could occur if they too were topped slowly. > >>> >> >At any rate I never seem to dive my gas until they show the correct > >>> mixture. > >>> >> > > >>> >> > > >>> >> > > >>> >> >"SILT HAPPENS"JD JEFF DISLER > >>> >> > SAFE CAVING NSS 26000 > >>> >> >-- > >>> >> >Send mail for the `techdiver' mailing list to > `techdiver@aquanaut.com'. > >>> >> >Send subscribe/unsubscribe requests to > `techdiver-request@aquanaut.com'. > >>> >> >-- > >>> >> >Send mail for the `techdiver' mailing list to > `techdiver@aquanaut.com'. > >>> >> >Send subscribe/unsubscribe requests to > `techdiver-request@aquanaut.com'. > >>> >> > > >>> >> > >>> >> ------------------------------------------------------------------- > >>> >> Learn About Trimix at http://www.cisatlantic.com/trimix/trimix.html > >>> >> > >>> >> -- > >>> >> Send mail for the `techdiver' mailing list to `techdiver@aquanaut.com'. > >>> >> Send subscribe/unsubscribe requests to > `techdiver-request@aquanaut.com'. > >>> > > >>> > > >>> > > >>> > > >>> > >>> ------------------------------------------------------------------- > >>> Learn About Trimix at http://www.cisatlantic.com/trimix/trimix.html > >>> > >>> -- > >>> Send mail for the `techdiver' mailing list to `techdiver@aquanaut.com'. > >>> Send subscribe/unsubscribe requests to `techdiver-request@aquanaut.com'. > >> > >> > >> > >>-- > >>Send mail for the `techdiver' mailing list to `techdiver@aquanaut.com'. > >>Send subscribe/unsubscribe requests to `techdiver-request@aquanaut.com'. > >> > > > > > > ------------------------------------------------------------------- > > Learn About Trimix at http://www.cisatlantic.com/trimix/trimix.html > > > > > >-- > >Send mail for the `techdiver' mailing list to `techdiver@aquanaut.com'. > >Send subscribe/unsubscribe requests to `techdiver-request@aquanaut.com'. > > > > > > > > > -- > Send mail for the `techdiver' mailing list to `techdiver@aquanaut.com'. > Send subscribe/unsubscribe requests to `techdiver-request@aquanaut.com'. -- Send mail for the `techdiver' mailing list to `techdiver@aquanaut.com'. Send subscribe/unsubscribe requests to `techdiver-request@aquanaut.com'.
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