I don’t know about air purifiers specifically, but long ago I worked on a lot of color television sets. The picture tube anode voltage was around 75,000 volts and it was sometimes difficult to keep it contained. It was common practice to darken the shop and inspect for leakage currents. A corona discharge looked like a faint fuzzy bluish area and presented a continuous extra load to the H.V. power supply. A streamer discharge looked like miniature blue lightening bolts and presented a sudden instantaneous load that caused the picture to suddenly shrink. Corona discharge sometimes faintly crackled but was generally silent. Streamer discharge made audible snaps. Both smelled strongly of ozone. There were a variety of paints, putties, and chemical sprays used to remedy the problem.
I don’t know about air purifiers specifically, but long ago I worked on a lot of color television sets. The picture tube anode voltage was around 75,000 volts and it was sometimes difficult to keep it contained. It was common practice to darken the shop and inspect for leakage currents. A corona discharge looked like a faint fuzzy bluish area and presented a continuous extra load to the H.V. power supply. A streamer discharge looked like miniature blue lightening bolts and presented a sudden instantaneous load that caused the picture to suddenly shrink. Corona discharge sometimes faintly crackled but was generally silent. Streamer discharge made audible snaps. Both smelled strongly of ozone. There were a variety of paints, putties, and chemical sprays used to remedy the problem.