B5-18 
9. 
PREPARATION OF CHARTS 
Enter the correction found in (b), preceded by a minus sign 
whenever the mean virtual temperature is below 0°C, under 
the uncorrected thickness of the stratum. If the correction is 
negative, subtract it from the uncorrected thickness, if it is 
positive, add it to the uncorrected thickness. Enter the sum or 
difference immediately below the correction. 
Enter the altitude for the highest standard isobaric surface on 
the printed isobar, within the last 10° space on the right side 
of the adiabatic chart, pertaining to that surface. Enter the 
corrected thickness obtained in(c)just abovethis altitude entry. 
Add the two entries and place the sum on the terminating level 
of the raob. This sum is the altitude of that level. 
PUNCHED 
CARD No. 7 
Figure B5 - 7. Entry of Maximum Altitude 
Extrapolation of Altitude Data, Extrapolated altitude data will be 
computed from the terminating level of the ascent to the next higher (with 
respect to altitude) mandatory constant pressure surface when the dif- 
ference between terminating level and the constant pressure surface is: 
=> 68) 
25 mbs or less up toandincluding the 100 mb surface. 
1/4 (or less than 1/4) of the pressure value of the mandatory 
constant pressure surface for levels above the 100 mb level. 
FMH#3 
