B3-8 BALLOON INFLATION AND ASSEMBLY OF TRAIN 
operates normally when supporting the weight of the radiosonde. Then 
rewind the twine by rotating the reel manually. 
9.1 Shock Unit for Train Regulator. A shock unit may be used in the 
radiosonde train between the regulator and the radiosonde if the vibra- 
tion caused by the regulator produces unstable signals. The shock unit 
may be formed by tying together in parallelfour 1/8'' wide rubber bands. 
Tie the bands to the cord of the train so that the cord is slack between 
the ends of the bands, permitting them toact as a shock absorber. 
10. Balloon Covers or Shrouds. The radiosonde balloon cover or 
shroud is designed to protect the radiosonde balloon while it is being 
moved to the point of release, andto aid in releasing it under conditions 
of high winds. The cover or shroud consists of a hood and four flaps, each 
of which terminate in a hand hold. 
10.1 Placing the Balloon in the Cover. Toplace the balloon in the cover, 
the bottom portion of the segments should be untied and the balloon 
lowered as near the floor as possible. Two of the segments should be 
pulled to one side and the balloon then allowed to rise under the cover. 
The cover supporting cord is then unsnapped and pulled free of the loops 
on the top of the cover. 
10.2 Drying the Shroud. If the cover or shroud becomes wet, it should 
be suspended loosely until it is thoroughly dry. 
10.3 Types of Balloon Covers. Two types of balloon covers are avail- 
able. The antistatic treated balloon covers will be used at radiosonde 
stations using hydrogen. The untreated shroud will be used at stations 
using helium. 
DANGER. Do not use the untreated shroud with hydroger filled balloons. 
Lo ntooy FMH#3 
