B2-12 
PREPARATIONS FOR SOUNDING 
8.1 Baseline-Check Recorder Entries. Draw a horizontal line across 
the recorder record parallel to the horizontal lines printed on the re- 
corder paper and at the top of the last baseline relative-humidity trace. 
a. 
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Draw straight lines connecting the top left edges of the tem- 
perature, humidity, and low reference traces that comprise 
the baseline-check. Extend the lines through the horizontal 
line drawn in accordance with the preceding paragraph. 
At approximately the tenth ordinate and immediately above the 
horizontal line, enter the notation ''Baseline-Check,"' followed 
by the time, to the nearest minute (GMT), that the baseline- 
check was completed. 
When a manual baseline-check is made, enter ''manual"' just 
to the left of the baseline-check ordinate values. 
Read the temperature ordinate to tenths and enter the value 
on the horizontal line immediately to the right of the line con- 
necting the left edge of the temperature traces. Following the 
temperature ordinate, enter the proper recorder correction, 
an equal sign, and the corrected temperature ordinate value. 
Enter another equal sign followed by the baseline-check dry- 
bulb temperature value. Example: 71.5-0.1 = 71.4 = 23.6°C. 
Recorder corrections of 0 will not be entered. 
Read the humidity ordinate value at the intersection of the 
horizontal line and the line connecting the left edges of the hu- 
midity traces. Enter this value just below the horizontal line, 
under the temperature ordinate value, followed by the appli- 
cable recorder correction, an equal sign, and the corrected 
ordinate. Enter another equal sign followed by the baseline- 
check psychrometric-humidity value. Recorder corrections of 
0 will not be entered. Enter all valuesin parentheses as shown 
in the following example: (77.3-0.3 = 77.0 = 34%). 
The entries of the baseline data will be spaced out to prevent 
obliteration of any part of the baseline record. 
Normally, the person reading and recording the baseline data 
will be the same person that evaluates the flight portion of the 
recorder record. 
FMH#3 
