{TAIL ~ The change} in the intensity of {HEAD ~ the individual wave lengths} of radiation comprising said spectrum, with time, is monitored to determine the characteristics of the kerogen sample being analyzed 
{ TAIL ~ The change } in the intensity of { HEAD ~ the individual wave lengths } of radiation comprising said spectrum , with time , is monitored to determine the characteristics of the kerogen sample being analyzed
TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH