Re: Helium loss

Steve G8KHW / AJ4XE

As the picoballooners have found - gas loss through diffusion on the ground is completely different in floating flight.  A foil balloon might loose 1g of lift (out of the 10g or so it was filled with) over 24 hours on the ground under no pressure - yet stay up for months in the air - under 0.2 psi differential pressure.

    Steve G8KHW

On 22/09/2022 22:49, BASE_DePauw wrote:

Although we did not take the time to do repeated trials, earlier this summer we filled a 200 gram Cloudbuster with helium indoors and set it for an initial 200 grams of positive lift.  24 hours later the lift was only 100 grams.  After an additional 24 hours the lift was 50 grams.  One more day and there was no lift at all.

We did not treat the balloon with the HiFloat solution.


On Thu, Sep 22, 2022 at 5:21 PM Steve G8KHW / AJ4XE <steve@...> wrote:



On 22/09/2022 21:53, Joe WB9SBD wrote:
If I remember correctly Hi Float is just HE and air , nothing special. so the HE will still escape just as fast and left with an envelope filled with air.


On 9/22/2022 3:52 PM, rich.m.legrand@... wrote:
Hi Steve, thanks for the information!  That's an interesting suggestion about Hifloat -- it looks like it could make a significant difference.

Howard L. Brooks
Professor of Physics and Astronomy
241 Julian Science and Mathematics Center
DePauw University
2 E. Hanna Street
Greencastle, IN 46135
(765) 658-4653

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