B4-16 RELEASE AND RECORDER RECORD 
Whenever the surface temperature is colder than -37.2°C and whenever 
the evaluation of relative humidity has been discontinued because the 
temperature has fallen to colder than -40°C, and the temperature again 
rises, the evaluation of the relative humidity willnot be resumed unless 
the temperature becomes warmer than -35°C. If however, it is resumed, 
the first level after resumption will be placed within the -37 to -40°C. 
portion. The level for the beginning or the resumption of relative hu- 
midity must be placed at the lowest pointnecessary to provide the max- 
imum data for the CPD blocks. When the surface temperature is -37.2°C 
Or warmer and the temperature falls to colder than -40.0°C within the 
first ten millibars of the flight, a level will not be selected to show the 
last measurable humidity of that portion of the flight. 
7. Evaluating the Recorder Record. Usable record will be obtained 
and evaluated to the highest altitudes possible. A second release will be 
required whenever the raob terminates at a pressure higher than (WB 
225 mb) or (AF, N 60 mb) or fails to meet the other conditions of doubt- 
ful and missing data as prescribed in the following paragraphs. 
7.1 Requirement for Satisfactory Flight. While evaluating the recorder 
record, the observer will be alert for evidences of conditions that will 
necessitate a second release. Whenever necessary, a second radiosonde 
will be released as promptly as possible inorder to stay within the time 
limits of scheduled observation (see §B4-1 for instructions concerning 
delayed observations). However, if because of unfavorable atmospheric 
conditions or other reasons, it is apparent that a pressure equal to or 
less than225mb or60mb, as applicable (see §B4-7), cannot be attained 
in subsequent attempts, an additional release will not be made. Ifa 
second release is not made and the record from the first one is usable, 
even though it did not extend to a pressure equal to or less than 225 mb 
or 60 mb, as applicable, the record from the first release will be evalu- 
ated and used for summary and transmission purposes. When a second 
release is required but not made, the reasons for the omission will be 
stated fully in the remarks section of the adiabatic chart for the first 
release, if evaluated; otherwise, on the adiabatic chartfor the next suc- 
ceeding raob. If a second and succeeding release does not reach the re- 
quired minimum altitude, the ascension providing the greatest amount of 
data will be evaluated and used as the official observation. In this case 
a note will be placed on the first fold of the recorder record of each 
flight giving a full explanation. 
U2 Left Edge of Traces Used for Evaluation. As inthe baseline- check 
evaluation, the left edge of the recorded traces will be used for all eval- 
uations during the flight. 
Ios iY) FMH#3 
