At 9:20 AM +0200 8/6/98, Dr. Rainer Woitok wrote:
>Hi all,
>
>On Wed, 1998-08-05 14:31:37 EDT, GMBulley@aol.com wrote:
>
>> ...
>> Both JC Whitney and (many) camping store sell self-adhesive, temperature
>> dependant stickers. They are actually designed for voiticle (verticle)
>>tanks,
>> but would give you *some* idea of what's in the tank.
>
>According to my experience this doesn't  work at all.   The idea is that
>the state transition  from the liquid to gaseous phase caused by propane
>consumption is acompanied  by a temperature drop  in the  gaseous phase.
>But   either a stove doesn't draw   enough  propane per  minute for this
>effect to be measurable by such  a crude device or  the metal of the gas
>tank does not clearly enough carry on this steep temperature gradient to
>the outside.  In any case forget these stickers :-(

In contrast, I've had good experience with these stickers. A couple things
have to be done though:

1) put it on a clean tank, not the undercoating.
2) use boiling water to check the guage.

As far as I know the temperature drop of the evaporating propane has
nothing to do with the measurment. Mine was used by splashing boiling water
over the guage. The deal is that the higher thermal mass of the liguid
filled tank pulls the heat away quickly cooling that part of the guage, and
the relative low thermal mass of the steel tank heats up and shows hot for
a longer time. The result si a distinct color change line at the liquid
level of the tank.

I always thought it would be good to put a small funnel with a pipe from
near the sink to above the guage so that boiling water could be poured from
inside. Then you could go outside and look at the guage.

my .02
 -Otmar-
72(front),73(rear) Stretched bus (almost sold)
86 (front) 82 (rear) Stretch GTI Westfalia soon to be running!
The frame is welded and it rolls :-)
Several EVs (Electric Vehicles)
http://www.evcl.com/strvan/strvan.html
http://www.evcl.com/Picprev.html
Electric Vehicle Components Ltd. (650) 494-9255