The invention is based on the recognition that {HEAD ~ an extremely rigid construction} of {TAIL ~ the measuring cell} is not necessary, provided that the compensation of the exterior pressure variations is carried out with sufficient accuracy 
of
The invention is based on the recognition that { HEAD ~ an extremely rigid construction } of { TAIL ~ the measuring cell } is not necessary , provided that the compensation of the exterior pressure variations is carried out with sufficient accuracy
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL 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