{HEAD ~ Small perturbations} in the drive voltage are applied at {TAIL ~ a level} to cause a measurable variation in the sensor output current 
are applied at
{ HEAD ~ Small perturbations } in the drive voltage are applied at { TAIL ~ a level } to cause a measurable variation in the sensor output current
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH