b) illuminating the sample within said test element with {HEAD ~ light} of {TAIL ~ NIR wavelengths}, 
of
b ) illuminating the sample within said test element with { HEAD ~ light } of { TAIL ~ NIR wavelengths } ,
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH