To define a stable position of the draft shield element on the sample changer, the seating rim of the draft shield element sits in {HEAD ~ a matching seating recess} of {TAIL ~ the sample changer} 
To define a stable position of the draft shield element on the sample changer , the seating rim of the draft shield element sits in { HEAD ~ a matching seating recess } of { TAIL ~ the sample changer }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL