The graph of FIG 4 represents magnitude values of the output of the analog to digital converter 44 as {HEAD ~ the media} 12 is transported in {TAIL ~ the longitudinal direction} from its initial starting point 
is transported in
The graph of FIG 4 represents magnitude values of the output of the analog to digital converter 44 as { HEAD ~ the media } 12 is transported in { TAIL ~ the longitudinal direction } from its initial starting point
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH