This applet permits you
to check the lift possibility of the balloon at your location
it need:
The difference between ambient temperature
and standard altitude (delta I.S.A. Celsius)
The altitude (feet)
The difference between ambient temperature
and the temperature inside the envelope (it is about 20 Celsius with good
sun conditions)
Balloon weight (40 kilograms for all
balloons at present time)
Envelope volume (2200 cubic meters for all
balloons at present time)
The applet will return
Approximation of ambient pressure at selected
altitude (in hg and hpa)
Approximation of ambient density at selected
altitude (slugs/ft3 and kgs/m3)
Approximation of ambient air temperature
at selected altitude (Celsius)
Approximation of inside air temperature at
selected altitude (Celsius)
Approximation of true inside air temperature
at selected altitude
taking account of the increase of sun radiation and the lower envelope heat
loss
due to the reduced convective loss in thinner air (Celsius)
Approximation of basic envelope lift (envelope
weight accounted for)(kgs)
Approximation of true envelope lift taking
account of the increase of sun radiation (kgs)
The standard ascent or descent velocity is around 200ft/ min
the cold descent is 600ft min