Verify Geiger counters to full CPM range - use a plasma ball

Have you ever tried to get a plasma ball near your Geiger counter?
I got mine to 250000 CPM (SMB 20) just by touching the plasma ball with one finger and the Geiger tube with another finger from another arm!
Getting plasma ball and tube together and I got a max 600000 CPM.
Impressive, no need to get Fiesta ceramic to try out the counter . Good to check software and communication protocols...

Check on internet, looks like plasma balls are not dangerous, but still they emit ionizing radiation.

Just pop a compact fluorescent light bulb next to the plasma globe and watch it light up

All those low energy electrons and high frequency photons working their magic.

Plasma ball produces electromagnetic interference, seems the counter is sensitive to EM noises.
If you want to verify your counter full CPM range use alfa tube with some alfa source or radium source, usually it goes over 150K cpm for americium. I'm sure that EM source is not really test the geiger counter ability, yes it can test the microprocessor counting, but it's not load HV circuit.