BALLOON INFLATION AND ASSEMBLY OF TRAIN Bobi 
neck since the strain on the film will cause premature bursting. Rather, 
the balloon should be allowed to rest against the ceiling of the inflation 
room, provided the ceiling is smooth and free from projections or rough 
spots. If the ceiling is not smooth, then the balloon should be allowed to 
rest against the balloon cover. If no cover is available, then a sheet or 
some other suitable material may be used to protect the balloon. Do not 
use a balloon for a later observationif the observation for which the bal- 
loon was inflated was missed. The balloon should not be inflated more 
than one hour prior to the time of the expected release. 
6. Launching Device and Flow Meter. If a launching device and flow 
meter are used, be careful when placing the balloon in the launching de- 
vice to insure that the balloon is not twisted and that it is not tangled in 
the launching shroud. Instructions on the operation and use of the launch- 
er and flow meter will be issued by the using service. 
Tle Assembly of Train. Use as long a train as the release conditions 
will permit, up toa maximum lengthof 120 feet. In order to avoid erron- 
eous temperature readings, trains of less than 70 feet in length must 
never be used and the parachute must be tied not more than 5 feet below 
the balloon. When the release must be made in high winds, a train regu- 
lator may be used. When a train regulator (see §B3-9) is used, the train 
will be assembled as follows: Tie the endofthe doubled 5-foot length of 
cord, which was used to tie the neck of the balloon to the upper end of 
the parachute. Tie the lower end of the parachute to the upper eye or 
spacer bar of the train regulator, and tie the free end of the cord from 
the train regulator to the ring on top of the radiosonde. 
8. Parachutes. Parachutes will be used at all stations and on ship- 
board unless specific instructions to the contrary are issued. 
oF Radiosonde Train Regulators. The radiosonde train regulator con- 
sists of a frame, reel, and braking mechanism. The regulator is fur- 
nished with approximately 60 feet of twine or nylon tape wound on the 
reel. The braking mechanism permits the weight of the radiosonde to 
unwind the twine at the nominal rate of 12 feet per minute. The regulator 
is designed to withstand the stresses placed on it in normal use. Care 
must be exercised to avoid unnecessary strains, which might ruin the 
gear train and braking mechanism. Before using, test the regulator by 
firmly pulling about 5 feetofcordfrom the reel, Should the reel feed out 
too rapidly, it may be adjusted by squeezing the metal braking pawls 
together with a pliers. If the braking pawls are too tight, the regulator 
will not feed out. To use, place the free end of the twine through the eye 
or over the spacer at the bottom of the regulator. Tie the twine to the 
supporting ring at the top of the radiosonde. Determine that the regulator 
ots O8) FMH#3 
