{HEAD ~ a detector} responsive to an air pressure condition within said passage to change a state of said detector under a predetermined pressure condition related to a fullness of {TAIL ~ said collector}, said detector including: 
{ HEAD ~ a detector } responsive to an air pressure condition within said passage to change a state of said detector under a predetermined pressure condition related to a fullness of { TAIL ~ said collector } , said detector including :
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH