{HEAD ~ The method} further comprises measuring {TAIL ~ the first and second components} based on the error signal and the repeatable component 
comprises measuring
{ HEAD ~ The method } further comprises measuring { TAIL ~ the first and second components } based on the error signal and the repeatable component
HEAD HEAD HEAD HEAD HEAD HEAD OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH