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