Hydrogen inflation equipment, generator, nozzles and weights
Below is a illustration of a hydrogen inflation system including nozzles weights and a regulator for use with compressed gas cylinders. A sounding balloon is a 300 gram or greater balloon used for carrying a radiosonde (instrument package) to altitudes.
Different weights are required to prepare Pilot balloons (30 gram and 100 gram balloons) for Day use no lighting unit attached or night time use with a lighting unit attached, filled with Hydrogen or Helium. Helium filled balloons require greater free lifts to achieve the same ascent rate. This is because helium has less buoyancy than hydrogen, hence a helium balloon with the same free lift as a hydrogen filled balloon will be larger and ascend more slowly. See also Hydrogen Safety Precautions.
| Specified freelift for balloon ascents taken from FMH No. 3 May 1997 (U.S.) | ||||
| Helium Day | Helium Night | Hydrogen Day | Hydrogen Night | |
| 30 gram (180m/min) | 139 grams | 192 grams | 125 grams | 170 grams |
| 100 gram (280m/min) | 515 grams | 552 grams | 450 grams | 482 grams |
Army and Marine met. units are issued a ML-373/GM nozzle set illustrated above left. This nozzle set is manufactured to produce an ascent rate of 300 m/minute not 280 m/minute as used by other weather services.