roswell

may ditter markedly from the problems ot surface measurement. For example;
tor any instrument used on a floating balloon, same consideration must be
given to the effect of solar radiation on its behavior. As mentioned in
the discussion of the automatic ballast valve, this effect is especially
important in the action ot any aneroid or other capsule which is not com-
pletely temperature compensated. Since the floating balloon will remain
within one parcel of air, rising and falling and moving sidewise as iile
air does, temperature extremes will result tram radiation effects and lack
9
ot ventilation. One investigator has estimated that the temperatures to
be experienced by such a bQdy range tram -60°C after a night of radiation
to a maximum of .f.so0 c in direct sunlight. Two ways of partially circum-
venting the undesirable results of this feature are:
1. Temperature compensation of the pressure capsule for some pre-set
5
pressure. T:his compensation is only complete at one pressure.
2. A second method of reducing insolation effects is the use of
highly reflective shields.
The meiilods of height determination used so far are not completely
satisfactory. Pressure-heights have been obtained by 72 me. and 397 me.
radiosonde transmitters with long-lite battery packs. Difficulties have
been experienced in all long flights due to:
l. Signals being lost due to excessive range or to pOM•er failure.
2. ~~en the balloon begins to float and height oscillations result
from the action of the automatic balla.st valve, it is impossible
to identify the radiosonde contact (hence the pressure) using the
conventional baroswitch of the Diamond-Hinman type radiosonde.
These steps are now being taken to improve height measurements:
1. The addition to the .flight train or a light-weight barograph.
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