First, Mark, I would not worry about 100g balloons and KD helium. The 100g balloons seem to leak less helium so maybe they will not need as much top off. BTW, the standard working inflation diameter for a 100g weather balloon is just 30" but this allows for expansion as the balloon ascends.
But, we should look at the numbers for the lift. Roughly, one gets 29g of lift for each CF of volume (I know I mixed English and metric units and am using mass for force). A 100g balloon filled to 39" diameter holds 3.9CF more helium than a 3' latex balloon filled to 36" diameter. This means the 100g balloon has 113g more lift. However, 3' latex balloon weighs 32g, so the 100g balloon needs to lift 68g extra weight so the net gain in lift is just 45 grams. Of course, the 100g balloon inflated to 39" is far from the burst limit of 52" while the 3" balloon is close to bursting. The more normal 33" inflation diameter for the 3' latex balloon give a lift difference of 138g which is significant given a total net lift capacity of 284g v. 422g for the 33" latex and 100g balloons respectively.
33" latex: volume: 10.9CF net lift: 284g
36" latex: 14.1CF 377g
100g (39"): 18.0CF 422g
The above numbers also show the importance of topping off during an event.
Leo
--- In Indoor_Construction_at_yahoogroups.com, "Mark F1diddler" <f1diddler@...> wrote:
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> --- In Indoor_Construction_at_yahoogroups.com, "Leo Pilachowski" <leop@> wrote:
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> > A 39" diameter balloon takes 27% more helium to fill than a 36" diameter balloon; 18.0 CF vs. 14.1 CF. >>
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> I still use the 100 grammers, and that after trying the smaller balloons but couldn't steer as well up high. Will be glad to send more money to the KD Helium club if my 100grammers seem to be a problem to anyone.
> MB
>
Received on Thu Mar 28 2013 - 09:12:37 CET
This archive was generated by Yannick on Sat Dec 14 2019 - 19:13:47 CET