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