{HEAD ~ The output signals} from {TAIL ~ transducers} and are used by data processing unit to compute the total concentration of hydrocarbon gases and vapors and the concentration of methane gas within cells and  
from
{ HEAD ~ The output signals } from { TAIL ~ transducers } and are used by data processing unit to compute the total concentration of hydrocarbon gases and vapors and the concentration of methane gas within cells and
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH