You stop being so cheap, pony-up and buy a Super-deluxe-doubles-tank shaking
device. Well worth the investment as it also doubles as a storage place for
your tanks. (Holds four sets) and a fun mini-marry-go-round ride for the
kids when not being used for mixing.  FWIW- it's a lot easier to sell the
wife on it if you tell her it is for the kids, and you will only use it
after they're done. :-)
-----Original Message-----
From: Jim Cobb <cobber@ci*.co*>
To: Jeff Waugh <jrwaugh@ix*.ne*.co*>
Cc: Steve Hogan <Steve.Hogan@tr*.co*>; pdisler@io*.ne*
<pdisler@io*.ne*>; silent@cu*.ne* <silent@cu*.ne*>; Tech Diver
<techdiver@aquanaut.com>
Date: Saturday, April 10, 1999 9:56 AM
Subject: Re: Trimix Question


>So, how do you roll a set of doubles?
>
>   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'.
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`techdiver-request@aquanaut.com'.
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`techdiver-request@aquanaut.com'.
>>> >
>>>
>>>  -------------------------------------------------------------------
>>>  Learn About Trimix at http://www.cisatlantic.com/trimix/trimix.html
>>>
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>>
>>
>>
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>
>
> -------------------------------------------------------------------
> Learn About Trimix at http://www.cisatlantic.com/trimix/trimix.html
>
>
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