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