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