The apparatus 1 in which said predetermined potential is between {TAIL ~ 200 V} and 600 V and said alternating potential has an amplitude comprised between {HEAD ~ 200 V} and 600 V peak and a frequency between 100 Hz and 1500 Hz 
The apparatus 1 in which said predetermined potential is between { TAIL ~ 200 V } and 600 V and said alternating potential has an amplitude comprised between { HEAD ~ 200 V } and 600 V peak and a frequency between 100 Hz and 1500 Hz
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH