When it is judged that the integral value exceeds a predetermined maximum value, the controller causes {HEAD ~ a display device} to display {TAIL ~ the necessity} of emptying the container 
to display
When it is judged that the integral value exceeds a predetermined maximum value , the controller causes { HEAD ~ a display device } to display { TAIL ~ the necessity } of emptying the container
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH