Flight Manual for Gas Balloons of Type NL-STU
Issue 2.0
May 02, 2016
Page 6-5
6.10 Instruments
6.10.1 Altimeter
Altimeters measure the static air pressure that decreases as the altitude increases. Mechanical
and electronic altimeters with corresponding certification can be used, provided that they meet
the specific operational requirements.
6.10.2 Variometer
Variometers measure the rate of climb and descent of the balloon. Electronic and mechanical
variometers that meet the specific operational requirements are to be used.