Apparatus 1, in which {TAIL ~ the inlet} is at {HEAD ~ a potential} in the range 0 1 KV 
Apparatus 1 , in which { TAIL ~ the inlet } is at { HEAD ~ a potential } in the range 0 1 KV
OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH