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