An angle α is then obtained between the dust bag and wall and the space thereof is filled with {TAIL ~ pressure sensors} that create signals used in indicating {HEAD ~ relative fullness} as previously described 
An angle α is then obtained between the dust bag and wall and the space thereof is filled with { TAIL ~ pressure sensors } that create signals used in indicating { HEAD ~ relative fullness } as previously described
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 OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH