When the temperature reaches {TAIL ~ a higher cleaning range} that is sufficient to burn {HEAD ~ the accumulated particulates}, the elapsed time that the temperature remains within such range is stored in a second counter 
When the temperature reaches { TAIL ~ a higher cleaning range } that is sufficient to burn { HEAD ~ the accumulated particulates } , the elapsed time that the temperature remains within such range is stored in a second counter
OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH