RELEASE AND RECORDER RECORD B4-9 
adjusted trace is recorded before the signal switches to the temperature 
circuit. In no case will the low reference be adjusted before a portion of 
the trace needing adjustment is recorded. If the ascension rate is so high 
that the recorder low reference traces are too short to provide a read- 
able record both before and after adjustment, an adjustment will not be 
made. Similarly, an adjustment will not be made when the low reference 
trace is so scattered or unsteady that there is doubt as to the actual 
value of the low reference ordinate. If the reference was adjusted to 95.0 
ordinate, and the radiosonde switches to temperature before a portion of 
the adjusted trace could be recorded, anetation, (Adj.), will be placed at 
the point of adjustment. 
5.2 Recorder Zero. It is necessary, during the observation, to occa- 
sionally examine the sprocket holes of the paper to see if the paper is 
creeping up on the pins. If it is, turn the proper switch momentarily to 
obtain a record of the recorder zero. If the drift appears to be uniform 
and 0.3 ordinates or more, paper drift corrections will be applied (see 
§ B4-17). If the paper drift does not appear to be uniform, make the best 
possible estimate of the drift and apply the drift correction as required. 
Paper drift is a result of misalignment of the chart paper with respect 
to the sprockets on the chart drum, caused by the misalignment of the 
paper supply roll. Adjustment controls are provided to permit correct 
alignment of the supply roll with respect to the chart drum sprockets. 
5.3 Recording Low Ordinate Values. On some types of recorders, it is 
difficult to obtain a trace at low ordinate values (below 5 ordinates). In 
this case, and in this case only, it will be permissible to draw the mis- 
sing trace with a hand held pen. The trace will be drawn where the pen 
was observed to be atthe time. A notation will be placed on the recorder 
record indicating the portion of the trace that was drawn by hand. In no 
case will the sensitivity of the recorder be reduced to obtain this trace. 
6. Selection of Significant Levels. Significant levels are placed on the 
recorder record to mark the boundaries of strata having differing tem- 
perature lapse rates or vertical humidity gradients. 
6.1 Identification of Significant Levels. Identify the significant level 
by drawing a line completely across the recorder record at that point. 
6.2 Surface. The first significant level is the point of the balloon's 
release. Determine from the recorder record the contact value at re- 
lease and enter it on the surface level slightly to the left of the ordinate 
equivalent of the surface temperature and in the appropriate block on 
WBAN-31A. Determine the recorder values of the observed surface 
1-1-69 FMH#3 
