{TAIL ~ Particulates} accumulate in the trap 2 over a period of time, and, the extent of accumulation of the particulates is detected by {HEAD ~ the pressure sensors} 11a and 11b 
{ TAIL ~ Particulates } accumulate in the trap 2 over a period of time , and , the extent of accumulation of the particulates is detected by { HEAD ~ the pressure sensors } 11a and 11b
TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH