Balloon
From Glossary of Meteorology
balloon
A flexible bag often made of rubber or plastic, which, when filled with helium, is used to carry meteorological instruments. See anchor balloon, ballonet, ceiling balloon, constant-level balloon, extensible balloon, jimsphere, kytoon, pilot balloon, racoon, robin sphere, sounding balloon, super-pressure balloon, tetroon, zero-pressure balloon.
Term edited 1 February 2022.