When the temperature is within a normal burning range, the elapsed time that {HEAD ~ the temperature} remains within {TAIL ~ such range} is stored as a first count whose magnitude is proportional to the accumulation of particulates 
remains within
When the temperature is within a normal burning range , the elapsed time that { HEAD ~ the temperature } remains within { TAIL ~ such range } is stored as a first count whose magnitude is proportional to the accumulation of particulates
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH