means for supporting a sample in a position to be illuminated by {HEAD ~ the infrared radiation} in {TAIL ~ either the transmission mode} or the reflectance mode 
in
means for supporting a sample in a position to be illuminated by { HEAD ~ the infrared radiation } in { TAIL ~ either the transmission mode } or the reflectance mode
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH