It is intended to employ a system of detecting a property of fuel in the course of a pipeline, while improving accuracy and stability of the fuel property detection. Disclosed is a device which comprises a sub-tank (7) provided in the course of a fuel pipe...

The method involves moving a restrictor body (30) e.g. piston and membrane piston, in a cavity (28) from a predetermined position (42) to another predetermined position (44), such that a shear flow of fuel is obtained in a gap (52) between the restrictor b...