Excerpt from the paper: "When switching the plasma on, the whole system needs time to stabilize. This (supposedly mostly thermal) stabilization process is monitored based on a plot of the absorbed electrical power displayed live on the computer screen (for details on the power measurements see references [6, 20]). The power changes on the timescale of minutes when the system is not stable yet. At first startup, the jet is operated at the given parameters for approximately half an hour prior to the first measurements [10]. When the system has been already running for a longer time and the operating parameters are changed, the stabilization time shortens to around 10 to 15 minutes."