Patent ID: 8226289

Claim:
A pVT cell for testing of fluids at high pressure including a piston ( 1 ) and a stirring system for rapidly providing equilibrium prior to test measurement, said stirring system comprising: an impeller ( 10 ) mounted for rotation on a shaft ( 11 ) in an impeller recess ( 2 ) on a fluid side of said piston ( 1 ), said impeller ( 10 ) including at least one permanent magnet; at least two driving solenoids ( 3 ) inside said piston ( 1 ), for influencing said at least one permanent magnet and thereby providing impeller ( 10 ) movement; and a monitoring solenoid ( 5 ) arranged inside said piston ( 1 ) close to but isolated from the impeller recess ( 2 ), in order to monitor the rotation of the impeller ( 10 ).