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