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