A3=-2 RAWINSONDE BALLOONS 
film thickness of these balloons is extremely thin, being from two-to 
four-thousandths (.002 - .004) of an inch thick when inflated for release 
and decreases to a thickness of one ten-thousandths (.0001) of an inch at 
bursting altitude. To state it more graphically, the film of the balloon 
at release is thinner than an ordinary piece of writing paper, and at 
bursting altitude, it would take 100 thicknesses of the film to equal the 
thickness of a punch-card. Additionally, the balloonexpands in size from 
an approximate release diameter of 6 feet to an expanded diameter of 
24-32 feet at bursting. It isnothardto see that the smallest cut, bruise, 
or scratch sustained during preflight preparation is almost sure to re- 
sult in the balloon bursting at a lower altitude than it normally would 
have attained. The requirement for careful preflight handling of these 
balloons cannot be overemphasized. 
1-1-69 FMH#3 
