roswell

Operation of the instrument may be described as follows: 7he
instrument is inserted in the load line just above the ballast
assembly by attaching the load line to the upper ring (A) and the
rigging from the ballast assembly to the lower ring (B). A canti-
lever spring (F) is set into an adjustable base (K), Which may be
adjusted tor various empty ballast-assembly weights by changing the
setting of the adjusting screw (L). The lower ring is attached
to the cantilever spring, but can be adjusted tor different ballast
weights by sliding along the spring (trom G to Gl, tor instance).
For light ballast weights the lower ring 1s moved away from the
base (K) (to the right on the diagram), and tor heavy ballast weights
it is moved toward the base. Adjustments are made on the adjusting
screw {L) and the lower ring {G) before each flight according
to the weights of the ballast assembly and the ballast.
The cantilever spring is attached to the connecting bar {E) at {H).
Thus the deflection of the lower ring is transferred through the
cantilever spring to the connecting bar and then to the pen arm
{C), which is pivoted about a fixed point {D). !he deflection is
recorded by the pen on a rotating smoked drum {B) • In order to
prevent the pen from going ott the drum, an adjustable stop is set
at {J).
The unit should be calibrated tor ~imum load {pen arm at Ct),
a medium load {pen arm at C) and minimum load {pen arm at C2) before
each flight. A trace of ballast function will start at the top of
the drum and as ballast is discarded will fall toward the bottom
ot the drum. By measuring the deflection at any time and comparing
with the calibration, the amount of ballast lett in the assembly
at any time can be determined. Since this instrument is a part
ot the bare-thermograph, the trace obtained upon recovery will contatn
information concerning altitude, temperature, and ballast tunc tioning
over the complete flight. After proper correction for time dis-
placement of the three pens has been made, the three types of in-
tor.mation can be correlated to give a fairly complete picture of
the balloon flight, including reasons tor various types of motion.
It is expected that this inatrument will be extremely valuable in
determining ballast control operation over a long period of time,
especially after the balloon system is out ot radio reception range.
It also will give information that could not·be obtained it there
were any failure of the autome.tic siphon meter or the transmitter
during launching or flight. The chief drawbaok of the instrument
is that information is dependent on recovery.
At the time of writing of this report the inst!"U1118nt has not been
flight tested. Preliminary laboratory tests indicate that the in-
strument will live up to the high expectations placed upon it.
Since the instrument actually records the tensile force in the load
line during flight, it may also be valuable in analysis of the ac-
celeration forces induced during periods of balloon oscillation
in the atmosphere.
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