Techniques for measuring {HEAD ~ a density} of a liquid within a fluid that includes both a liquid and {TAIL ~ a gas} are described 
Techniques for measuring { HEAD ~ a density } of a liquid within a fluid that includes both a liquid and { TAIL ~ a gas } are described
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH