RELEASE AND RECORDER RECORD B4-23 
7.8.2 Sticking Contact Arm. A rough commutator bar, foreign matter 
on the commutator bar, and a rough point on the contact arm are some 
factors which may cause sticking or retarding ofthe contact arm. Many 
of the characteristics of this malfunction are completely opposite to 
those of a leaking pressure cell, i.e., lower contact values (higher pres- 
sures) will be recorded than should be indicated. If a contact arm 
"sticks", it usually remains in this position for a time and the contact 
becomes excessively long. If itbecomes unstuck, it jumps to the ambient 
pressure and either misses or passes over the intervening contact very 
quickly. Thus, uneven or missing contacts usually result. These uneven 
contacts should not be confused with turbulence or possible vertical cur- 
rents. Whenever, in the best judgment ofthe observer, the pressure data 
are believed to be incorrect because of a sticking contact arm, all data 
from the beginning of the suspect portion ofthe record will be classified 
as missing. 
7.8.3 Electrical Leakage in the Baseline-Check Box. Moisture or some 
other foreign material in the radiosonde baseline-check box test plug 
and/or switch may cause electrical leakage. When this condition exists, 
the temperature ordinate value will be recorded at a higher value than 
should be indicated. The baseline-check temperature-ordinate relation- 
ship is then incorrect and will result in temperature evaluations aloft 
which are all toocold, and, asaresult, there will be an increasing error 
in the computed altitude data. When the temperature ordinate equivalent 
of the actual surface temperature is consistently lower than the temper- 
ature ordinate value at release, the electrical leakage checks should be 
made, 
7.8.4 Repeated Contacts. Repeated contacts are aresultofa faulty baro- 
switch assembly. When the recorder record indicates a repeat of contacts 
which are not associated with the balloon descending and then reascend- 
ing, data will be classified missing above the point where the repeat 
began. The data below this point will be considered accurate if the re- 
peated portion was three contacts or less. All data of the flight will be 
classified as missing when the repeated portion is more than three 
contacts, 
7.9 Classifications for Other Unusual Situations. Recorder records 
showing unusually steep lapse rates (either positive or negative) that 
must be evaluated as accurate are: 
a. Wet Bulb ''Supers'. All "supers" which appear to be the re- 
sult of a “wet bulb'' effect willbe evaluated as recorded on the 
recorder record and the data classified as accurate. A "wet 
bulb" effect may occur when the instrument goes from a moist 
environment into one which is relatively dry. The ideal situ- 
ation for this type of moisture change often occurs at the top 
= 69 FMH#3 
