wherein {HEAD ~ positioning} of {TAIL ~ the plunger} within the chamber is artificially controlled by the positioning device to allow the volume of the enclosure to be pre determinable 
of
wherein { HEAD ~ positioning } of { TAIL ~ the plunger } within the chamber is artificially controlled by the positioning device to allow the volume of the enclosure to be pre determinable
OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH