Flexible balloon filling devices from Graw Radiosondes : Graw Radiosondes

Secure attachment of the ballon and easily adjustable counterweight
Suitable for a wide range of balloon sizes and payloads
SO-2 is a stationary unit suitable for both helium and hydrogen
SO-3 is a mobile unit for helium exclusively

Ballon filling devices are located at the interface between weather balloon and the gas supply. They provide an easy way to hold the ballon nozzle during inflation and adjust the balloon's neck lift accordingly. As calculating the neck lift can be tedious, there also is an extensive documentation for different sounding setups and environmental conditions. Depending on the configuration, both hydrogen and helium can be used with the devices.

Key specifications
SO-2	Installation unit, hydrogen or helium lift gas
SO-3	Mobile unit, helium lift gas
Ballon compatibilty	3 cm neck diameter, 1.4 cm neck diameter (SO-3 only)

Technical data SO-2
Storage size	580 x 580 x 405 mm
Weight	5.0 kg (without box and accessories)
Balloon compatibility	3 cm neck diameter (200g - 1500g balloon)
Lift gas	Hydrogen or helium

Technical data SO-3
Storage size	350 x 300 x 150 mm
Weight	4.8 kg (including box and pressure regulator)
Balloon compatibility	1.4 cm and 3 cm neck diameter (100g - 1500g balloon)
Lift gas	Helium