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