The ozonesonde is a lightweight, balloon-borne instrument that is mated to a conventional meteorological radiosonde. As the balloon carrying the instrument package ascends through the atmosphere, the ozonesonde telemeters to a ground receiving station information on ozone and standard meteorological quantities such as pressure, temperature and humidity. The balloon will ascend to altitudes of about 115,000 feet (35 km) before it bursts.
An ozonesonde consists of a Teflon air pump and electrochemical ozone sensor interfaced to a meteorological radiosonde. The small piston pump bubbles ambient air into the sensor cell containing 3 milliliters of 1% potassium iodide solution. The reaction of ozone and iodide generates an electrical signal proportional to the amount of ozone. The radiosonde measures air temperature, pressure, relative humidity and transmits all of the ozone and weather data back to a ground receiving station during the 2 hour weather balloon ascent.