Note that different installations are
used depending on the components of the sounding. Always use an unwinder. You must use an RSU
stabilizer if you use other than Vaisala-specific Totex parachute models.
Before you begin, see the general
instructions and various sounding accessories presented in Guide to Sounding Preparations Technical Reference
(M211367EN).
The sounding construction depends
on the radiosonde type and if either of the following is used:
Radar reflector
Parachute
Vaisala recommends always to
use a parachute in ozone soundings.
When using a Totex parachute, attach the unwinder to the ribbon loop below the
parachute spreader.
As the accidental breaking of the unwinder hook may cause the ozone sounding box to
fall with great speed, Vaisala recommends that you tie the unwinder to the parachute
spreader with a string for extra security.
CAUTION For extra security, Vaisala
recommends that you tie the radiosonde unwinder to the Totex parachute spreader with a string,
or tie extra strong tape around the unwinder hook.
Thread the string through the hole in the unwinder hook, (circled in the following
figure), and tie it around the parachute spreader. Make sure that the string is
slightly longer and looser than the ribbon loop.
Another option is to prevent the unwinder hook from opening during the flight by
tying extra-strong tape such as glass cloth tape, or equivalent, around the unwinder
hook. If you do not have this kind of strong tape available, tie the unwinder with a
string to the spreader, as explained above.
If you like, you can also use both options at the same time.
Securing unwinder with string (on
the left) or tape (on the right)
Assemble the unwinder detainer to the radiosonde unwinder by pressing the detainer head
into the radiosonde unwinder.
If you are using other than a Vaisala-specific Totex parachute model, or a radar
reflector, connect the RSU stabilizer to the unwinder and prepare the balloon string
connection.
RSU stabilizer attached to the
unwinder
When EN-SCI Model Z ozone sensor is used,
the unwinder string is firmly attached to the ring hanger.
Continue sounding preparations by tying the flight box string to the unwinder
pin.
Balance the radiosonde payload
by moving the string knot on the bottom of the flight box, and secure it with a piece of
tape.