Editing Weather balloon (section)

== Materials and equipment ==
The balloon itself produces the [[lifting gas|lift]], and is usually made of a highly flexible [[Latex (rubber)|latex]] material, though [[chloroprene]] may also be used. The unit that performs the actual measurements and [[Transmission (telecommunications)|radio transmissions]] hangs at the lower end of the string, and is called a [[radiosonde]]. Specialized radiosondes are used for measuring particular parameters, such as determining the [[ozone layer|ozone]] concentration.

The balloon is usually filled with [[hydrogen]], though [[helium]] – a more expensive, but viable option nonetheless – is also frequently used.  The ascent rate can be controlled by the amount of gas with which the balloon is filled, usually at around {{convert|300|m/min}}.<ref name="AWH">{{cite web |title=FAA-H-8083-28A, Aviation Weather Handbook |url=https://www.faa.gov/regulationspolicies/handbooksmanuals/aviation/faa-h-8083-28a-aviation-weather-handbook |publisher=[[Federal Aviation Administration]] |access-date=27 December 2024}}</ref>{{rp|24-54}}  Weather balloons may reach altitudes of {{convert|40|km|abbr=on}} or more, limited by diminishing pressures causing the balloon to expand to such a degree (typically by a 100:1 factor) that it disintegrates. In this instance the instrument package is usually lost,<ref>{{Cite web |last1=Dabberdt |first1=W F |last2=Shellhorn |first2=R |last3=Cole |first3=H |last4=Paukkunen |first4=A |last5=Horhammer |first5=J |last6=Antikainen |first6=V |date=2003 |title=Radiosondes |url=http://www.radiopassioni.it/pdf/materialirsonde/Radiosondes.pdf |publisher=Elsevier Science Direct}}</ref> although a parachute may be employed to help in allowing retrieval of the instrument. Above that altitude [[sounding rocket]]s are used to carry instruments aloft, and for even higher altitudes satellites are used.