Abstract: Device for measuring liquid volume in the manner of a cylindrical piston meter with a cylindrical measuring chamber with connecting channels running perpendicularly to the cylinder axis of the measuring chamber and with a cylindrical piston inserted eccentrically into the measuring chamber and performing a wobbling movement, said piston having an H-shaped cross section and a through opening for engagement into a separating wall projecting into the measuring chamber, with the characterizing feature that the cylindrical piston is hydraulically tensioned by the inflowing liquid in the measuring chamber and the pressure differential on the outer and inner jacket surfaces of the cylindrical piston tends toward zero.