{HEAD ~ Flux sensors} generate {TAIL ~ signal variations} corresponding to flux variations as the forcer moves relative to the teeth of the platen 
{ HEAD ~ Flux sensors } generate { TAIL ~ signal variations } corresponding to flux variations as the forcer moves relative to the teeth of the platen
HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH