{TAIL ~ A processor}, connected to each of the pressure sensors, sorts a relative difference between signals of {HEAD ~ the sensors} during dust filling 
{ TAIL ~ A processor } , connected to each of the pressure sensors , sorts a relative difference between signals of { HEAD ~ the sensors } during dust filling
TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH