The unwinder must be attached firmly, so
that it is not able to twist freely, or the string may unwind at too high a speed and the
radiosonde hit the ground during the launch. The unwinder must be able to swing slightly
during the sounding. Follow the steps and figures below to attach and align the unwinder
correctly when it is attached directly to the balloon.
Pass the unwinder hook through the loop created by the tied balloon neck.
Make sure that the hook comes out the other side, as shown in the following
figure.
The unwinder is now firmly attached to the balloon.
Align the unwinder so that it points directly downwards from the balloon neck.
CAUTION To ensure a
successful sounding, align the unwinder so that it points downwards from the balloon
neck.