auuuu Index
Early Balloons
Military Use of Balloons
Scientific Use of Balloons
Ballooning as a Sport
Ballooning Records
Long-distance records
Zero-pressure balloons
Superpressure Balloons
Uses of Scientific Balloons

Zero-pressure balloons

The zero-pressure plastic (usually polyethylene) balloon is used to make measurements of the atmosphere as the balloon travels horizontally. The plastic balloon is filled only partly with gas while on the ground. As the balloon ascends, the expanding gas fills the envelope. This type of balloon has a valve that automatically discharges excess gas when the balloon reaches a certain altitude, so that the balloon can maintain this altitude as it travels horizontally. When the Sun sets, the gas cools, the volume decreases, and the balloon falls to the ground, unless ballast is released.

Hot air ballooning

eXTReMe Tracker Ballooning auuuu.com2006.